How this compresses without uploading anything

Most compressors send your file to a server, shrink it there and send it back. This one does not. Your browser already ships with a JPEG and WebP encoder, and this page simply asks it to re-save your image at the quality and width you pick.

That has one consequence worth stating plainly: there is no upload, so there is nothing to leak, nothing stored and nothing to delete afterwards. You can confirm it — open your browser's network tab, compress a file, and watch that no request goes out.

It also means the tool works offline once the page has loaded, and that a 20 MB photo does not have to travel twice across your connection before you see the result.

WebP or JPEG: which one to pick

Google reports that lossy WebP files come out 25 to 34 % smaller than a JPEG of comparable quality. WebP is supported in every current major browser, so for anything going on a website it is the better default, and it is what this tool selects for you.

JPEG is the right choice when the file has to be opened by something older or fussier — a print shop, a marketplace that rejects WebP, an internal system nobody wants to touch. It is a little heavier at the same quality, and universally accepted.

One thing this tool will not pretend to do: if you feed it a PNG and ask for a PNG back, almost nothing happens. PNG is a lossless format, so there is no quality dial to turn. To make a PNG meaningfully lighter you have to change format, which is why WebP is offered instead.

How far to push the quality slider

Quality 80 is the setting to start from. On photographs it typically removes most of the weight while leaving nothing you would notice on a screen. Below about 60 the damage starts to show on skies, skin and flat gradients — the smooth areas go blotchy first.

Screenshots, logos and anything with sharp text behave differently. Lossy compression smears the edges of letters, so those want a higher setting, or a format built for flat colour.

The honest way to use the slider is to move it and look at the result, rather than trusting a number. Compress the same file at 80 and at 60, open both, and decide with your own eyes which one you would be happy to publish.

Why width usually matters more than quality

A photo straight from a phone is often 4.000 pixels wide. The place it ends up — a product card, a blog post, a category listing — might draw it at 600. Every pixel beyond what the screen actually paints is weight nobody sees.

Resizing before compressing is the single biggest saving available here, and it is why the tool offers a maximum width alongside the quality slider. Set it to something close to the size the image will really be displayed at, and the quality setting matters far less.

Doing this once is easy. Doing it forever is the problem

Compressing a handful of files by hand works fine. It stops working when the images arrive every week, when somebody else uploads them, or when the same picture has to exist at four different sizes for four different screens.

That is the job NimboCDN does on a WordPress site: it prepares each image at the size the visitor's screen will actually draw, in the format their browser accepts, and serves it from our side instead of yours — as WebP on the free plan, and AVIF on Pro, which is usually lighter still. You install the connector and the delivery changes; nothing in your library is rewritten.

If you want to know whether it is worth it for your site, the image size checker measures the bytes your pages send today and estimates what they would weigh afterwards.

Questions

That is a byte measurement. Not page speed. Not image quality. The sample and the limits stay beside the finding.

Why we measured instead of reading comparisons

We needed to decide which platforms should get a connector. Published comparisons gave us conflicting answers, including on whether Shopify served AVIF.

So we measured storefronts. The first result overturned the assumption in our plan: one platform described as doing little had eight ready-made widths and served WebP. Building from the comparison would have cost months.

A platform that already handles its images has no problem for our connector to solve.

What bytes per pixel measures

Bytes per pixel is the size of each delivered image divided by its pixel count, summarized as the median for a storefront. It lets us compare encoding weight without rewarding a store just for using smaller pictures.

It does not measure quality. A low number can mean efficient encoding or a damaged image. It is not a savings estimate either. We left “what NimboCDN would save” out of the table because that would require a model, not a direct measurement.

The measured table

Medians across stores. n counts stores, not images. Rows with one or two stores are shown, but they do not describe a platform.

Two columns matter. Bytes per pixel shows delivered weight. “Already modern format” shows how often the platform had already moved beyond JPEG or PNG.

How the sample compares with the wider web

The HTTP Archive Web Almanac reports bits per pixel across more than ten million pages. Our figures are bytes per pixel. Multiply by eight and the units match.

The Web Almanac puts the median image at 2.1 bits per pixel and the median JPEG at 2.0. WooCommerce in our sample sits at 2.01. Shopify sits at 0.75, below the report's 1.4 median for AVIF.

This does not make Shopify “faster.” It says its storefront images carried fewer bytes per pixel in this sample.

What this does not prove

• Most platform samples are small. Shopify has 12 stores, VTEX 6, and WordPress plus WooCommerce 7. A one-store row is only that store.
• We measured storefronts. Product pages, checkout, and dashboards can behave differently.
• This is not a savings estimate. It says what arrived, not what another service would remove.
• Bytes per pixel is not quality or load time. Those need different measurements.

What the result changed

It closed more platforms than it opened. All 12 Shopify stores already used modern formats. Wix, Squarespace, and Webflow both delivered reasonably and left no place for an outside connector to change image delivery.

WordPress and WooCommerce showed the clearest gap among the platforms with a usable sample, and both allow a connector. That supported the market we were already serving. It did not prove every WordPress store has the same problem.

For the practical next step, read what images can and cannot fix on a slow WooCommerce store, or rule out the other causes of a slow WordPress site.

Weigh your own storefront

Your store is not a median. Paste one page into the website image size checker. It weighs every image and encodes the heaviest ones for real. Today's number is measured. The possible after is estimated, with its error shown.

If the site runs on WordPress, install the connector. No account. No credit card. The home page starts shipping lighter right away. If you prefer to work inside the media library, compare ShortPixel and Imagify.

Questions

That split matters. Categories, product pages, and the home page carry images by the hundred. Checkout, cart, and the WordPress dashboard do not.

We measured the storefront side. Across 41 real stores on 14 platforms, the 7 WordPress and WooCommerce stores — a small sample, and we say so — sent 2.5 to 2.7 times more bytes per pixel than the 12 Shopify stores. No stopwatch. Just image bytes.

Is it the checkout, or the storefront?

Open the page that is slow. The answer starts there.

If checkout is slow, an image CDN is not the fix. Ours included. Check plugins, database queries, and hosting instead.

On the storefront, the largest visible element is often a product image. Google calls the moment it appears Largest Contentful Paint (LCP):

LCP measures the time from when the user initiates loading the page until the largest image or text block is rendered within the viewport.

— web.dev, Google's guide to optimizing LCP.

We do not measure how long your store takes to open. We measure image bytes. Load time also depends on the hosting, theme, scripts, and everything else on the page. The product image is simply a heavy part we can weigh.

What store images actually weigh

One real product image arrived as a 1,536 px JPEG weighing 176 KB. At the 800 px the screen needed, the AVIF version weighed 15.9 KB. That image was 91% lighter at the same perceived quality.

One image is not a catalogue. So we tested format separately: 14 images from two real stores, encoded 336 ways, with perceived quality equalized at SSIMULACRA2 70.

Width matters too. Old uploads often keep traveling at their original size. We set a cap because we measured the alternative: for a 324-pixel space, the browser chose an image 42% heavier than another version the platform already had.

The math of a category page

Multiply the measured image by forty and the arithmetic gets loud. This is an illustration, not a measurement of a forty-image category on your store.

The same images also appear on product pages, search results, and related-product blocks. Repetition turns one heavy file into a catalogue problem.

What fixing it means for a store

Three things have to happen to every image. Re-uploading the catalogue is not one of them.

1. Use the size the screen shows. Never send a wider version than the site already has ready.
2. Use a lighter format. WebP on the free plan. AVIF on Pro, about 21% lighter than WebP in the measured comparison above.
3. Deliver from a network, not the store's server. Each image is prepared once. After that, our network — 335 cities in more than 125 countries — sends it to visitors. We measured the boundary: once the image is on the network, the store's server receives no request for it.

This does not make a promise about checkout speed. It removes image delivery from the server. Those are different claims.

The free plan covers the home page, up to 50 new images a month in WebP. Category and product pages need the whole-site Pro plan: $9.90 a month, one price, AVIF, with no charge per visit, bandwidth, or image.

Weigh your store's images

Paste a category or product page into the website image size checker. It weighs every image there and encodes the heaviest ones for real. Today's number is measured. The other is estimated.

The estimate's median error is 6.2 percentage points for AVIF and 10.2 for WebP, measured on eight stores the model had not seen. That limit belongs next to the number.

If a blog post is the slow page, read why a WordPress site can feel slow. If you want to work inside the media library, the ShortPixel and Imagify comparison explains where each tool does the work.

1. Paste the category or product page with the most images.
2. Read both numbers. See which images carry the weight.
3. If the store uses WooCommerce, install the connector. No account. No credit card. The home page starts shipping lighter right away.

Questions

Hosting, plugins, the theme, the database, the cache: all five can cause trouble. None is the only weight on the page.

A store uploads hundreds of product images. A blog adds more with every post. On most pages, those files are the heaviest thing there.

We measured it. On a real home page — a small site with nine images — those images weighed 2,323 KB. At the size each screen draws and in a lighter format, the same nine weigh 281 KB. That is 88% less image weight on every visit. Image by image. The method is in this article. So is the estimate's error margin.

What Google looks at on a slow page

Google takes speed into account. The number is Largest Contentful Paint (LCP): how long the largest thing on screen takes to appear when someone opens the page.

LCP measures the time from when the user initiates loading the page until the largest image or text block is rendered within the viewport.

— web.dev, Google's guide to optimizing LCP.

In plain English: the largest image or block of text. On a store, that is usually a product image. On a blog, it is often the image at the top.

We do not measure how long your site takes to open. We measure image bytes. We say that here because page-load time also depends on your hosting, theme, plugins, and everything else the page loads. Those image bytes are often the largest part traveling.

Is it the images, or something else?

Check before you install anything. Guess wrong, and you can spend a month fixing the wrong problem.

Three checks. All free.

You can have both: heavy images and a slow plugin. Order matters. Weighing first costs nothing.

How heavy are WordPress images, really?

We measured image weight on 41 real stores across 14 ecommerce platforms.

The WordPress and WooCommerce stores — 7 stores, a small sample, and we say so — sent 2.5 to 2.7 times more bytes per pixel than the 12 Shopify stores. Between 0% and 48% of their images used a lighter format. Shopify was at 100%.

That extra weight comes from two places: the file is larger than the screen, and it is still a JPEG when lighter formats exist.

Format is something we can count. Same perceived quality — not the same quality setting, which is the comparison that lies. Fourteen images from two real stores, encoded 336 ways, with perceived quality equalized at SSIMULACRA2 70:

Size does not mean “upload smaller images.” It means not sending more image than the visitor's screen can show.

We set a cap because we measured what happens without one: for a 324-pixel space, the browser chose an image 42% heavier than another version the site already had ready.

Your server ships images instead of working. It keeps sending image after image to every visitor when its job is to run the site.

That happens on your server. The next step is to take it off your server.

What fixing it actually means

Three things, for every image. Doing them by hand never ends: every new upload starts the work again. All three matter. The third is the one most sites miss:

1. The right size. The width the screen shows. Not the camera's width. Not whatever the theme uploaded. Never wider than a version your site already had.
2. A lighter format. WebP for everything. AVIF where it matters. Those choices come from the measurements above, not a rule of thumb.
3. Delivery from a network, not your server. Each image is prepared once. Then it leaves our network — 335 cities in more than 125 countries — for every visitor. Your server sees the image once. On later visits, it does not. We measured that too: once the image is on the network, the server receives no request for it.

No slogan. The visitor downloads less. The server sends less.

That is what an image network changes. Ten visitors or ten thousand at once: the images still come from the network.

Weigh your own site's images

Do not take our word for it.

Paste a page into the website image size checker. It weighs every image on that page, encodes the heaviest ones for real, and puts two numbers side by side: today's, measured; the other, estimated.

That estimate has a median error of 6.2 percentage points for AVIF and 10.2 for WebP, measured on eight stores the model had not seen. We publish the error. A number that hides it is not much of a number.

If the site runs on WordPress, the report offers the connector. Two minutes in the dashboard. No account. No credit card. The home page stays free forever: up to 50 new images a month, in WebP, sized for each visitor.

The whole site in AVIF is the Pro plan: $9.90 a month. One price. No charge per visit, bandwidth, or overage. Your original files stay untouched. Deactivate the connector and everything returns to the way it was.

1. Paste a page — the home page, or the category where the images are.
2. Read both numbers. See which images carry the weight.
3. If it runs on WordPress, install the connector. The home page starts shipping lighter right away.

Questions

Verdict: choose Imagify if you want local compression and do not need a CDN. Choose ShortPixel if you want cloud delivery and accept a credit meter plus a 500 GB monthly traffic cap. NimboCDN, our product, puts transformation and delivery in the cloud; its paid plan charges a flat fee without usage meters.

Why people compare these two

Both have a free plan and both make WordPress images lighter. The useful comparison is the unit: ShortPixel counts credits, while Imagify counts megabytes of new images. Price alone does not tell you which limit your site will reach first.

Method, and what we couldn't verify

Every competitor figure comes from WordPress.org, its official API, or the vendor’s pricing and policy pages. Installations, ratings and versions were checked on 4 September 2026. ShortPixel renders prices with JavaScript, so JJ Nieva verified them in a browser on 31 August 2026 and archived the capture; they were not available in the raw HTML. Imagify’s plans were present in its HTML. Claims without a first-party source were left out.

ShortPixel Adaptive Images

ShortPixel is the cloud option. Adaptive Images rewrites image URLs and serves resized, modern-format versions while the originals stay on your server. Its paid Unlimited offer publishes a 500 GB monthly CDN cap. When quota runs out, the plugin says it will serve the original images from your server, without compression or resizing, until the quota resets.

Imagify

Imagify is the library compressor. It optimizes files at upload or in bulk, then your server delivers them without a CDN. Its listing says originals move to a backup folder, provided the Backup option stays active. The free plan includes WebP and AVIF conversion within 20 MB a month.

NimboCDN — the row that does a different job

NimboCDN handles a third job: transformation and delivery. The connector rewrites image URLs; each image is prepared once for the requested screen and format, then served from our network in 335 cities across more than 125 countries. A cached image makes zero requests to the transformation service, which we measured. The original files stay unchanged, and deactivating the connector restores the original URLs.

ShortPixel also moves delivery off your server. Imagify concedes something we do not offer free: AVIF in its free plan. NimboCDN’s free plan covers the home page in WebP, up to 50 new images a month. The paid plan covers the whole site with AVIF for a flat $9.90 a month and does not meter visits, MB, GB or image count.

How to leave each one without losing anything

The exit story is part of the choice, not a footnote.

1. Leaving Imagify: restore from the backup folder, and check the option is active before you uninstall — their own listing says originals “can be restored at any time,” provided the Backup option stayed on. Then your server serves the original files again.
2. Leaving ShortPixel Adaptive Images: deactivate. The addresses revert to your own, and the untouched originals were always the ones being served from your server anyway.
3. Leaving NimboCDN: deactivate the connector. Every address goes back as it was, instantly, with nothing to clean up — verified in our own uninstall test: no leftover options, no temporary data, no scheduled tasks.

Which one fits which site

• If your pages are mostly photos uploaded once and never re-uploaded, and you want them optimized where they live: Imagify does that job, honestly and cheaply — count your MB first.
• If your site regenerates thumbnails often or you want delivery off your server with a metered plan: ShortPixel Adaptive Images — read the credit arithmetic and the 500 GB cap against your traffic before committing.
• If you want size, format and delivery handled elsewhere under a flat paid plan: install the NimboCDN connector. No account or credit card is required for the free home-page plan, and it starts serving right away.

And if you're not comparing tools yet — you're still weighing whether images are the problem at all — that question has its own piece, with the diagnostic and the measurements behind it. If it's a store full of product photos, the WooCommerce piece separates what images fix from what they don't. To weigh a specific page of yours before deciding anything, the website image size checker takes any URL and measures what its images really weigh — or read what that Lighthouse line about modern formats actually meant. And if the tool you are leaving is a third one, the five plugins compared by what each of them meters covers Optimole, Smush and EWWW as well.

Questions

The name changed. The job did not. Lighthouse finds older image formats and estimates what could be removed by converting them.

Google says it directly: “This audit has moved into the Improve image delivery insight as of Lighthouse 13.”

What the Lighthouse warning measures

The audit checks BMP, JPEG, and PNG images on the page. It then models the possible reduction from WebP and AVIF.

Lighthouse collects each BMP, JPEG, and PNG image on the page, converts each to WebP, and estimates the AVIF file size, reporting the potential savings based on the conversion figures.

— developer.chrome.com, the audit documentation.

The important word is estimates. The bytes your page sent are measured. The possible WebP or AVIF weight is not. Lighthouse also leaves an image out when the potential reduction is below 8 KiB, so the list focuses on larger opportunities.

What “next-gen” formats are

In this audit, they are WebP and AVIF instead of JPEG or PNG. The comparison only means something at the same perceived quality.

We tested that part ourselves: 14 images from two real stores, 336 encodes, with perceived quality equalized at SSIMULACRA2 70.

Those are file-weight measurements, not page-load times. We did not measure how long a site took to open. Hosting, scripts, caching, and the rest of the page still matter.

Browser support matters too. Google's audit notes that WebP, AVIF, and WebM do not work on iPhones below iOS 16. Delivery has to check what each browser accepts and keep the original as the fallback.

What to do in WordPress

Google's WordPress advice is to use a plugin or service that converts uploads automatically. Automatic is the useful part. Doing a catalogue by hand never ends.

Tools take different routes. Some rewrite files in the media library and keep backups. NimboCDN changes the image address at delivery time. The originals stay untouched, and deactivating the connector restores the old delivery at once. The ShortPixel and Imagify comparison shows how two library-based tools differ.

If a product category is the slow page, start with what images can and cannot fix in WooCommerce. For the whole site, rule out the other causes of a slow WordPress site.

Check the image bytes on your page

Paste a public page below. The checker weighs every image that travels and encodes the heaviest ones for real. Today's number is measured. The possible after is estimated.

That estimate has a median error of 6.2 percentage points for AVIF and 10.2 for WebP, measured on eight stores the model had not seen. The full method is on the website image size checker.

If the site uses WordPress, the report offers the connector. For a single file, the free compress image tool works without leaving your browser. Two minutes. No account. No credit card. The home page starts shipping lighter right away.

Today is measured: those bytes traveled. With NimboCDN is estimated, and the label stays beside the number.

Questions

Why your images carry extra bytes

A product photo often leaves the camera about 3,000 pixels wide. You upload it, and the platform keeps the original while generating six or eight smaller versions. That part works as intended.

The extra weight appears at delivery. A theme may choose a 1,536-pixel image for an 800-pixel slot. Format adds another gap: across 14 images from two real stores, WebP was 21.8% lighter than JPEG at the median when perceived quality was held at the same point. WebP won in 11 of those 14 comparisons. Your visitor downloads every extra byte.

On September 3, 2026, we measured the home pages of 41 stores across 14 platforms. The WordPress and WooCommerce stores served between 2.5 and 2.7 times more bytes per pixel than the Shopify stores. This was a small, uneven sample: 7 WordPress stores and 12 Shopify stores. Treat it as a measured signal, not a census.

Where those extra bytes land

Image weight has three direct costs.

LCP measures the time until the largest image or text block is rendered in the viewport, as the web.dev documentation explains. On a product page, that block is often an image. This checker measures image bytes. It does not measure page-load time or diagnose hosting, theme, or checkout performance.

Why a fixed percentage misses the result

Multiplying today's weight by one percentage is quick. It also treats every photograph, illustration, size, and format as if they compressed alike.

We tested that baseline on 8 stores held out from the model. Its median image-by-image error was 59.4%. The estimator on this page reduced that error, but its output remains a prediction and is labeled estimated.

Lighthouse, the Chrome tool behind the audit on next-gen image formats, documents two limits: it converts images to WebP but estimates AVIF size, and it omits images with potential savings below 8 KiB (developer.chrome.com). Measured bytes and estimated output need different labels.

How this checker measures image weight

The checker opens the page you provide in a real browser, sees the images your visitors see, and counts the bytes that were actually downloaded. It then resizes and encodes those images as WebP to estimate what they would weigh when delivered at the needed width.

1. We read one page. We open it in a real browser, so we see the images your visitors see — including the ones JavaScript inserts and the ones that load as you scroll. We do not crawl the rest of the site.
2. We weigh each image. We count the response bytes and read its real width and height from the file header.
3. We encode the image. The browser decodes it, reduces it to the width used by the page, and encodes a WebP file. Nothing about your site is changed.

Measured now, estimated after conversion

The current weight is measured: those bytes came from your server. The WebP weight is estimated. It comes from a real encode of every image we could read, then receives a small correction because the browser's encoder is not byte-identical to the delivery encoder. The corrected value is still a prediction, so estimated items keep that label in the report.

What the report includes

The total is backed by an image-by-image breakdown.

• Current and estimated totals, in kilobytes and as a percentage.
• Weight, dimensions, and format for every image the page downloads.
• An estimated label wherever the result is a model output rather than measured bytes.
• A report by email, available when you ask us to send it.
• The files the checker could convert to WebP, available to download for two days.

What the WebP result means

The main result uses WebP because that is the format included in the free plan. It estimates WebP at the width used by the page. In a separate test, AVIF was 21.8% lighter than WebP at the median across 16 derivatives from one real store, at the same width and perceived quality. That AVIF figure is a reference for the paid plan, not an estimate for the page analyzed here.

One file does not represent every screen

When a site provides responsive images, a browser downloads the larger source only when needed, as the web.dev documentation explains. The report lists the dimensions and format retrieved in this scan. A different screen may receive a different source from the same site.

How far the estimate can vary

We measured this checker against NimboCDN's own delivery: four sites we control, running the connector, with every image compared one by one against the bytes the network actually served. 256 images.

The image-by-image spread is the number to be careful with. Errors average out across a page, so the total is dependable and a single row is not — which is why the report labels per-image figures as estimated and the headline is what we stand behind.

The remaining gap is the encoder: a browser's WebP is not byte-identical to the one that delivers your images, and the correction for it depends on the kind of photography a site publishes. It is now a single constant of 1.035: the earlier version mixed the encoder with the resizing error, and that second error was removed.

This does not measure page-load time. It measures image bytes. Hosting, theme code, scripts, network conditions, and the rest of the page also affect how long a page takes to load.

From a measurement to lighter delivery

If you only want to fix one photo right now, the free compress image tool runs in your browser and uploads nothing. The report shows where the image bytes are. NimboCDN is the optional next step: it resizes, converts, and delivers images while leaving the originals unchanged.

NimboCDN is an image CDN for WordPress. Install the connector and activate it. Each image is then prepared once at the size and format needed by the visitor and delivered through our network of 335 cities in more than 125 countries. The original files stay on your server.

The free plan covers up to 50 new images a month on your home page in WebP. It does not expire, and there is no credit card. Traffic does not change the price. The paid plan covers the full site in AVIF for $9.90 a month.

• Original files stay intact. Nothing is recompressed, moved, or deleted.
• Turn it off in one click. Disable the connector and the original image URLs return right away.
• Automatic fallback. If the service cannot deliver an image, the connector serves the original.
• Fixed traffic cost. There is no charge per visit, per bandwidth, or for overage.

For a product-by-product comparison, see the alternatives to Optimole and ShortPixel versus Imagify. The first also covers what happens when an Optimole visit limit runs out.

What this page stores

We store the report and the page address included in it. Converted images stay available for download for two days and are then deleted. Files on your server are never changed.

This page uses Google Analytics and its _ga cookie to measure aggregate usage. We also retain the connecting IP address for 24 hours to enforce scan limits, then delete it.

Questions

Start with the page that matters most. If you want NimboCDN to handle the result, install the connector in two minutes. Your home page is free, with no credit card.

Those are Optimole's rules, not our interpretation. The recovery steps matter most if Image Offloading moved the originals away from your server.

What happens when you reach the limit

On the free plan, Optimole sends an email and gives you a few days to upgrade. If you do not, its official limit documentation says the original images return and optimized delivery is permanently deactivated for the account.

Paid plans do not stop delivery. They move to the next tier automatically:

Automatic quota upgrades for premium plans cannot be disabled. This is by design — it ensures your optimized images remain available without interruption when your site traffic exceeds your current plan limit.

The upgrade is billed separately through FastSpring and prorated for the days left in the cycle. That can look like a duplicate charge after renewal. Check the plan tier in the Optimole dashboard first.

Why images can go blank

After a limit event or deactivation, there are two documented places to look.

1. The originals are only in Optimole Cloud. Image Offloading can move them away from your server. Reactivate the plugin and transfer them back before deactivating again.
2. A cache still contains Optimole URLs. The deactivation guide says to clear the WordPress cache plugin, page-builder cache, host cache, CDN cache, and browser cache.

How Optimole counts visits

Optimole counts a unique user once per day, whether that person opens one page or twenty. Its counting documentation notes one exception: a large burst of requests from the same source, such as a scraper, can add more than one visit.

The total will not match Google Analytics because the tools measure traffic differently. The Optimole chart also defaults to the last 30 days, not the billing cycle. Use Current Billing Month to check quota use.

Three options

1. Move up a tier. This fits when the traffic increase is permanent and the price works. The current tiers are on Optimole's pricing page.
2. Remove unwanted counted traffic. If bots explain part of the count, Optimole's visit documentation shows how to identify crawler requests in logs.
3. Choose a different meter. If visits keep growing, compare what each service charges for. Our Optimole alternatives page puts five billing units side by side. NimboCDN is ours, so keep that bias in view: it costs $9.90 a month and does not count visits or bandwidth.

If you used Image Offloading, roll back first

Do not deactivate first. If the originals only exist in Optimole Cloud, that order can leave broken image URLs. Optimole's transfer guide gives this sequence:

1. Keep the plugin active and the API key connected. Confirm the domain is still under Allowed Domains.
2. Open Optimole → Settings → Image Storage. Choose “Optimole Cloud and your website,” then Transfer back from Optimole.
3. Wait for the transfer to finish. Deactivate only after the originals are back.

You can also request a ZIP export of the library from the Optimole dashboard.

NimboCDN takes a different approach: the original files never move. Install the connector with no account and no credit card. The home page starts shipping lighter right away. Deactivate it and the original image addresses return at once.

Questions

A cheapest-to-most-expensive ranking would compare unlike quantities. The useful question is simpler: which limit will your site reach first?

What each one actually charges for

All of them shrink images. What changes is what they count while they do it, and that column weighs far more on your bill than the big number in the shop window.

Read the middle column with your own site in mind. A magazine with 4,000 archived photos and 3,000 readers a month blows through Imagify’s megabyte cap without breaking a sweat, and never gets anywhere near Optimole’s visit ceiling. A landing page with nine images and 200,000 visitors is the exact opposite. Same two products, opposite verdicts. Which one suits you does not depend on the tool: it depends on what your site is made of.

What an image CDN is — and why it takes weight off your server

An image CDN is a network of servers spread around the world that optimizes and delivers your site’s images in place of your server. Each visitor gets the image from a point on the network, already converted and sized for their screen — and your server drops out of that equation.

The practical effect is a division of labor. Images are usually most of a page’s bytes — we weighed how many, on 41 storefronts across 14 ecommerce platforms — and without a CDN it is your hosting that ships file after file to every visitor — when its job is to run the site. With delivery delegated, your server is free for what actually matters: the catalog, the cart, the content. That is the difference between the two families in the table above: a compressor makes files lighter where they sit; a CDN optimizes and takes delivery off your server’s back.

Why the units do not convert

It helps to picture a chain. Someone arrives, loads a page, the page asks for images, the images travel as bytes. Each tool taps a different link:

Five meters in five places. That is why a “normalised” price table would have to invent how many images a page carries, how many bytes each one weighs and how many pages a visitor opens. No vendor backs those assumptions, and an invented assumption is not a comparison: it is a hunch with table borders.

Why people look for Optimole alternatives

Optimole has more than 200,000 active installations and a 4.7 rating on WordPress.org. This comparison does not measure product quality. It examines the billing model, where three limits tend to matter.

1. The ceiling arrived before the payoff. Paid plans start at 48,000 visits a month. Cross that and you move up a tier even if you have not uploaded a new image: the meter is on visitors, not images.
2. The free plan does not go far. Its listing offers a Free plan with all features – For sites with up to 2000 visits /month. You can push it to 22,000 visits, but only by showing Optimole’s badge on your site: generous on features, short on volume, and those extra 20,000 visits cost you a slot on your own page.
3. They wanted to be able to stop paying. Apart from EWWW’s local mode and ShortPixel’s one-off packs, everything on this list is a subscription.

A visit meter is not automatically a flaw. It is predictable when traffic is predictable. Optimole also names its delivery network — Cloudfront CDN (450+ locations). We publish the size of ours: 335 cities in more than 125 countries.

What happens when you go over Optimole’s visit limit?

Hitting the Optimole visit limit plays out in two very different ways depending on the plan. On the free one, Optimole emails you and gives you a few days to decide whether to upgrade. If you don’t, the official documentation says what comes next: Optimole will return your original images and permanently deactivate your account’s optimized image delivery — your originals come back, and that account’s optimized delivery is switched off for good.

On paid plans nothing gets cut off, and that is precisely the detail. Go over the quota and the subscription climbs on its own to the next tier, with a separate prorated charge processed by FastSpring. The documentation is explicit: Automatic quota upgrades for premium plans cannot be disabled. This is by design. The declared intent is good — your images keep serving without interruption. The side effect is declared too: what decides next month’s bill is your traffic, not you.

Not every tool reacts this way. ShortPixel, compared against Imagify, chose the opposite path: run out of quota and the plugin serves your originals straight from your server until the month resets. Nothing breaks, nothing gets pricier; your site just goes back to its old weight for a few weeks.

What your bill looks like as the site grows

With per-visit billing, the price does not track growth smoothly: it climbs in steps. These are Optimole’s published steps, with the automatic upgrade wiring one to the next:

Every step is a price Optimole itself publishes; none is our estimate. NimboCDN is not on that staircase because it charges a different unit — a flat $9.90 a month, with no visit meter — so lining the numbers up compares nothing. What you can compare honestly is the shape of the bill: in one model, a promotion that works or a post that goes viral changes next month’s amount; in the other, it doesn’t.

Where these numbers come from

Every figure on this page was read on the vendor’s own site or its WordPress.org listing on 31 August 2026, and every one is cited at the foot with its link. None of them comes from a review or a comparison site.

Prices move in this market, so the date is worth as much as the number. If you are reading this months later, check the vendor’s page before you decide.

Two things worth a second look if you compare on your own:

• Smush advertises “up to 500 GB” on its site, but each Pro plan says 50 GB and only Premium says unlimited. The plan card wins, not the headline.
• Optimole’s visit counts will not match Google Analytics, and their own documentation says why: the two tools measure traffic differently. If you are checking your quota, check it in their dashboard, not in your Analytics.

Optimole opens its pricing page with Boost loading times by 40%. That is Optimole’s claim, not our measurement. NimboCDN reports image bytes instead: page-load time also depends on the hosting, theme and every other resource, so we do not publish a speed multiplier.

Optimole

Who it is for. A large library, predictable traffic and no appetite for configuring anything. You want the CDN, the format conversion and the storage in one place.

It is an image CDN by design, not a compressor with delivery bolted on afterwards, and it shows. All three plans carry Unlimited Images & Sites, Image Offloading & Storage and Unlimited images on all plans with unmetered bandwidth: bandwidth is not metered; visits are. It converts to WebP and AVIF. And it leaves what you have on the server alone — without altering the original files on your server.

Two things the table does not say out loud. Serving images from your own domain with a CNAME only starts at Business, not at Starter. And the free plan is documented on its WordPress.org listing but does not appear on the pricing page, where only the three paid tiers show.

Verdict. Pick it if your traffic is predictable and your library is large. Skip it if your visits spike: that is exactly where the meter sits, on the part you do not control.

ShortPixel Adaptive Images

Who it is for. Anyone who wants something close to unlimited at a low, fixed price. And agencies, which often prefer buying credit once to carrying yet another subscription.

It is the only one in the group you can pay for in two ways: a monthly plan or a one-off purchase. The unlimited plan is US$9.99 a month, or US$8.33 if you pay yearly, with credits and sites uncapped. The fine print does carry a number, though: 500 GB of CDN traffic a month. The credits never run out; the delivery does.

It serves WebP and AVIF without you doing anything, by swapping image URLs; your original files stay on your server. And if the credits run out mid-month, nothing breaks: its own listing says the plugin will simply serve the original images from your server, without compression or resizing, until the quota resets. The same listing says the delivery network is bunny.net. Worth not mixing up: the Direct Cloudflare integration on its pricing page is a different thing — a token so your own Cloudflare pulls the updated images.

Verdict. Pick it if you want a fixed monthly price or would rather buy credits once. Skip it if you deliver more than 500 GB a month: that is the published delivery cap.

Imagify

Who it is for. Sites with heavy traffic and few new images. All the more so if you already run WP Rocket, which comes from the same team.

Imagify makes traffic irrelevant by a simple route: it does not deliver anything. It compresses your files and leaves them where they were, on your server. There is no CDN in the product. If you already have one, that is an advantage rather than a gap.

Two things before you pick it. The good one: AVIF conversion is in even the free plan — WebP and AVIF conversion included in the free plan — which is more than EWWW and more than my own free plan offer. The one that needs attention: Imagify automatically replaces the original images with an optimized image. There is a backup and a one-click restore, but by default it rewrites your library. That is a different kind of risk from everything else on this list, and it is worth deciding on purpose rather than discovering afterwards.

Verdict. Pick it if you already have a CDN or do not need one, and above all if you already run WP Rocket. Skip it if you are uneasy about it rewriting your originals by default.

Smush

Who it is for. Agencies with a fixed, known roster. It is the only one here that charges per site rather than per usage, and that makes it the only one whose bill you can project a year out.

One site is US$50 a year; three, US$75; ten, US$100. The Premium tier covers unlimited sites at US$4.99 a month. Every Pro plan includes 50 GB of CDN traffic, on a network they describe as Global CDN (119 nodes) without saying whose it is. It converts to WebP and AVIF and serves them on its own.

Its free version has a clear limit: In the free version, images over 5MB are skipped. Files above that threshold are left unchanged.

Verdict. Pick it if you need to know today what next year’s bill will be. Skip it if your roster grows fast: every new site adds up, heavily used or not.

EWWW Image Optimizer

Who it is for. Anyone who wants to optimise seriously without sending a single file to anybody’s cloud.

EWWW takes a different route: it is, in its own words, the only plugin that lets you optimize images using tools on your own web server. jpegtran, optipng, pngout, pngquant, gifsicle and cwebp, running on your own machine, free. If what bothers you about everything above is the dependency itself, the discussion ends here.

Its paid side is a CDN called Easy IO, billed by bandwidth: US$80, US$160 or US$320 a year for 50, 200 or 400 GB, with unlimited images and sites on all three tiers and overage at US$0.065 per GB on the top one. Check one thing before you pay: AVIF conversion is built into the Easy IO CDN. Here the modern format is not free.

Verdict. Pick it if your real objection is the dependency: in local mode nothing leaves your server and it costs nothing. Skip it if you want AVIF without paying.

NimboCDN

Stopping here to say it plainly: NimboCDN is mine. Read what follows with that suspicion in place, and check it against the entries above.

Who it is for. A store that wants no meter on it, where images and traffic can grow without the bill following them.

US$9.90 a month, or US$99 a year. Flat rate. Traffic is never counted.

That is not a commercial promise: it is how the thing is built. Each image is transformed once and stays cached for good. Once the image is cached — every visit after the first — no request reaches the transformation service, and that is measured in the experiment the price was built on. Ten visits and ten million cost the same, because visits were never what we were counting.

Your original files stay exactly where they are. They are not replaced, not moved, not uploaded anywhere.

You switch the connector off and everything goes back to how it was, in one click. If the service stops responding, the connector stops itself and your platform serves its own images. We tested the four worst cases — origin down, origin slow, corrupt file and invalid signature — and all four end on the original image. Never on a broken one.

On format: at equal perceived quality, measured with SSIMULACRA2 at 70, AVIF came out 32.1% lighter than JPEG at the median, winning on all 14 of the 14 images we tested, taken from two real stores, across 336 encodings. On the 9 images of a real home page, that was going from 2,323 KB to 281 KB.

Worth knowing before you try it. The free plan is a sample, not a usage tier: it covers your home page, up to 50 new images a month, in WebP. It is meant for seeing it work on the page that gets the most visits, no credit card and no commitment.

And if your site is small, or most visits land right on the homepage — the classic landing-page case — that slice covers what matters, and the free plan serves you perfectly well. The whole site and AVIF come with the paid plan, and there the price has no steps: US$9.90 a month, or US$99 a year, with no meter in the middle.

Verdict. Pick it if you want no meter on you and need images and traffic to grow without the bill following them. Skip it if what you are buying is track record: the connector is new and the other five have years.

Is switching simple? What changes and what doesn’t

Leaving Optimole is simpler than it looks, with one exception worth knowing before you deactivate anything.

If you never used their cloud storage, the exit is clean, and their own documentation says so: on deactivating the plugin, the image URLs will be reverted to the original URLs, and the images will serve from your own server. Your files never moved; what changes is who serves them. If some image still points at the old URL after that, it is cache — the caching plugin’s, the host’s or the browser’s — and clearing it fixes it.

The exception is Image Offloading, the Pro feature that moves your images into Optimole’s cloud. There, order matters: bring the files back first, deactivate second. The official path lives in Settings → Image Storage, choosing “Optimole Cloud and your website” and confirming Transfer back from Optimole; you can also request a ZIP export of the whole library from their dashboard. And keep your domain listed under Allowed Domains until the end — without it, their documentation warns, the rollback won’t run.

On this side, trying costs you nothing. The NimboCDN connector never moves or rewrites a single file — your originals stay where they are — and switching it off returns the site to its previous state in one click. The free plan covers your homepage forever, no credit card, precisely so you can watch it work before deciding. And the number that starts the whole decision is free either way: the image size checker weighs the images your own storefront serves today.

Which one should you pick?

Before the recommendation, the side-by-side of what each one delivers:

• Lots of images, modest traffic. Optimole. The visit ceiling is precisely the one you will not reach, and with bandwidth unmetered the size of the library stops mattering.
• Heavy traffic, few images. Imagify, or EWWW in local mode. Paying per visit to serve nine images is the worst possible fit.
• Both are growing and you want to stop thinking about it. NimboCDN’s paid plan has no cap on visits, images or traffic. ShortPixel stops delivery at 500 GB a month.
• A fixed roster of clients. Smush. It is the only one whose bill for next year you already know today.
• No third-party dependencies. EWWW local. Nothing leaves your server and nothing costs anything.
• You want AVIF without paying. Imagify: AVIF is in even the free plan.

Frequently asked questions