AI, Compression Quality, and Performance

ShortPixel and EWWW Image Optimizer are two of the most established image optimization plugins in the WordPress ecosystem, but they’ve taken very different paths to get where they are.

ShortPixel is cloud-based at every tier, feature-rich, and has expanded aggressively into AI-powered tools. EWWW started as a local-first plugin, compressing images directly on users’ servers since 2012 with no external API required, and has since added cloud compression and a broader performance toolkit on its paid plans.

That evolution matters for how you evaluate them. At the free tier, EWWW and ShortPixel are genuinely different tools. At the paid tier, both process images in the cloud, and the comparison shifts to feature depth, compression quality, and what each subscription actually includes.

By the end of this article, you’ll have a clear picture of what each plugin does well, where they genuinely differ, and which one makes more sense for your setup.

Comparing ShortPixel and EWWW Image Optimizer

Before getting into the detail, here’s a summary of how the two plugins compare across the main criteria. Keep reading for the full breakdown of each one below.

*EWWW’s local compression and Compress API don’t support AVIF. AVIF conversion is available with Easy IO CDN on paid plans.

**ShortPixel’s CDN is built into the main plugin. The separate Adaptive Images plugin adds dynamic device-aware sizing on top.

ShortPixel Overview

At 300,000+ active installs, ShortPixel is one of the more established image optimization plugins available for WordPress.

It offers a cloud-based compression solution where images are sent to ShortPixel’s servers, processed, and returned to your media library as smaller files. The originals are stored locally as backups, so nothing is permanently lost.

ShortPixel’s Compression and Format Support

ShortPixel gives you three compression modes to choose from.

• Lossy is what most sites should use. It produces the largest file size reductions, often dramatically so for JPEGs in particular, with quality loss that’s invisible at normal screen sizes. Blogs, marketing pages, news sites, and general portfolios all benefit most from this mode.
• Glossy sits between the two other compression modes. Its algorithm is more conservative about removing image data, which makes it the right choice for photography portfolios or WooCommerce product images where fine detail has commercial weight.
• Lossless compresses without touching image quality at all. The savings are smaller, but for logos, diagrams, technical screenshots, and anything where precision matters, it’s the best solution.

Something that catches people off guard the first time is that every image uploaded to WordPress generates multiple size variants automatically, and without an optimizer each one is stored at full quality. ShortPixel processes all of them in a single pass, which is where a lot of the performance savings accumulate on larger media libraries.

WebP and AVIF conversion are included at every plan tier, the free one included. PDF optimization is also supported alongside images, which is worth knowing if downloadable documents are part of your content.

For the more advanced users, ShortPixel keeps EXIF data by default, but it provides an option to strip it if you’d prefer lighter files.

ShortPixel’s AI Features

Where ShortPixel has expanded most aggressively in recent times is AI. All of the following tools are part of the same plugin installation with nothing extra required.

The AI image SEO feature generates alt text, captions, titles, and descriptions automatically across over 100 languages. It runs across your existing library in bulk and includes a preview mode so you can review results before they’re applied. For anyone managing a large media library with incomplete metadata, or publishing in multiple languages, this removes a significant amount of repetitive manual work.

Our WordPress Image SEO Checklist covers where automated alt text fits into a broader image SEO workflow.

The AI upscaling tool generates 2x, 3x, and 4x versions for high-DPI displays from lower-resolution source files, without needing originals shot at retina quality.

Meanwhile, the one-click AI background removal tool is particularly useful for product photography where clean, isolated images are the standard.

ShortPixel’s CDN and Delivery

ShortPixel’s CDN delivery works at two levels. The Image Optimizer plugin includes CDN as a built-in feature, serving your optimized images, CSS, JS, and fonts from bunny.net’s global network. For most sites that removes the need for a separate CDN entirely.

ShortPixel Adaptive Images goes further as a separate plugin. Rather than delivering pre-compressed static files, it generates a correctly-sized image for each visitor’s device on request, stores it on the CDN, and never writes the file to your server.

Every visitor gets an image sized to their exact container, which eliminates the guesswork in WordPress’s static srcset approach. Our responsive images guide explains the practical difference in more detail if you want to learn more.

ShortPixel’s Pricing

The free ShortPixel plan gives you 100 credits per month once you’ve added a free API key. Since WordPress creates multiple size variants per upload, each original image typically uses four to five credits, so that 100 credits covers roughly 20 to 25 actual image uploads per month.

Shortpixel’s paid options come in two forms. One-time credit packs start at $19.99 and never expire, which makes them well suited to a single bulk job on a large existing library rather than ongoing use. The Unlimited plan is $9.99 per month and covers unlimited images across all your websites with an ongoing subscription.

In either case, ShortPixel creates backups of your originals before compression, which adds to disk usage over time. Their recently introduced Smart Backups feature changes that since, instead of backing up every generated thumbnail, it saves only the main image and rebuilds thumbnails from it whenever it needs to restore them.

EWWW Image Optimizer Overview

EWWW Image Optimizer has been around since 2012, which is long enough to have a genuine track record and over 1,000,000 active installations to show for it. Its 4.8 out of 5 rating on WordPress.org is one of the highest of any image optimization plugin, and reviewers consistently mention that it works reliably in the background without needing attention.

What makes EWWW distinctive at the free tier is where the compression happens. It’s done directly on your own server, with no external API and no monthly quotas.

Upgrade to a paid plan, however, and EWWW’s Compress API sends images to EWWW’s own cloud servers for lossy compression, putting it in similar territory to ShortPixel from a processing standpoint. The differences at that stage shift to feature depth, compression quality, and what each paid plan bundles in.

EWWW’s Local Compression and the Free Tier

EWWW’s free tier compresses images using tools installed on your server itself. No signup, no API key, and no credit card required. Simply install, activate, and it starts working.

The compression here is lossless, which means file sizes are reduced without any quality change. For JPEG images, lossless savings are modest, but lossy compression — the kind that significantly reduces file sizes while keeping images looking sharp — requires the paid Compress API, which processes images on EWWW’s cloud servers.

WebP conversion is supported at all tiers, however, AVIF is only available through Easy IO CDN on paid plans.

EWWW’s Compress API and Easy IO CDN

When you upgrade to a paid plan, the Compress API takes over. Here, images are sent to EWWW’s servers and compressed with a lossy algorithm that produces substantially better results than local lossless. Independent benchmarks place EWWW’s PNG compression in second place overall, with competitive JPEG savings.

Every paid plan also includes Easy IO CDN, which handles image delivery from a global network, converts to WebP and AVIF on the fly, and scales images automatically to fit the visitor’s screen. The Standard plan covers 50GB of monthly bandwidth. Growth bumps this to 200GB and adds 100+ CDN locations and custom domain support. Infinite gives you 400GB, with overages at $0.065 per GB if you go over.

EWWW’s SWIS Performance Toolkit

This is where EWWW moves beyond image optimization entirely. All paid plans include SWIS Performance. It’s a full page speed toolkit that handles caching, JS and CSS minification, Critical CSS generation, deferred scripts, and more.

For site owners who want to reduce the number of plugins they’re managing, getting image optimization and broader page performance tooling from a single subscription is a genuine advantage.

EWWW’s Pricing

The free tier is as simple as it gets. Unlimited lossless compression across unlimited websites with no account required. When you’re ready for more, EWWW’s paid plans bring in the Compress API for proper lossy compression, Easy IO CDN for delivery, and SWIS Performance for broader page speed tooling.

• Standard: $8/month (or $80/year: 50GB CDN bandwidth, unlimited images, unlimited sites
• Growth: $16/month ($160/year): 200GB bandwidth, 100+ CDN locations, custom domains
• Infinite: $32/month ($320/year): 400GB bandwidth, the same features with more headroom

Everything is subscription-based and there’s no one-time purchase option, which is worth factoring in if you’re primarily looking to run a one-time cleanup of a large existing library.

Head-to-Head Comparison: ShortPixel vs EWWW

Compression Quality

Both plugins deliver meaningful results, but the starting points are different. EWWW’s free tier uses lossless compression, which achieves modest file size reductions. Independent testing from Image CDN puts the free-tier EWWW plugin at 8–18% compression on JPEGs, which is a significant constraint for most sites. Upgrading to the paid Compress API unlocks lossy compression and substantially better results.

ShortPixel holds a clear lead in JPEG compression across multiple independent benchmarks. OddJar’s 2025 WordPress image optimization comparison recorded ShortPixel at 54% JPEG file size reduction versus EWWW’s 44% on paid compression. That’s a meaningful gap on large image libraries.

A separate WPShout test recorded 83% savings for ShortPixel on a large JPEG versus 18% for EWWW using out-of-the-box settings. EWWW was more competitive on PNG compression, which is where had OddJar ranked it second overall.

Your results will always vary depending on image type, content, and settings, so testing on a sample of your own images before committing is always the right call.

WebP and AVIF Delivery

Both plugins support WebP conversion. AVIF is where they differ.

ShortPixel delivers AVIF at every plan tier including the free one, while EWWW’s AVIF support is tied to Easy IO CDN on paid plans. If AVIF delivery matters to your site, and for visitors on modern browsers, the file size difference is meaningful, ShortPixel is the more straightforward option.

Our image optimization tips guide covers image format choice in more depth.

AI Features

There’s no head-to-head to run here. ShortPixel has AI alt text generation in 100+ languages, AI upscaling, and AI background removal. EWWW has none of these.

For site owners who want image SEO metadata handled automatically alongside compression, ShortPixel is the only option of the two.

CDN and Delivery

Both plugins offer CDN delivery as a paid feature, but they approach it differently.

ShortPixel’s built-in CDN serves pre-compressed files from bunny.net’s network, with Adaptive Images adding dynamic on-the-fly sizing as a step up. EWWW’s Easy IO handles delivery, WebP/AVIF conversion, and responsive scaling from a larger CDN network, with 100+ locations on Growth and Infinite plans.

For sites where CDN coverage and bandwidth headroom are the priority, EWWW’s paid plans offer more infrastructure at a competitive price.

Performance Tooling

EWWW bundles SWIS Performance with every paid plan, covering page caching, JS/CSS minification, Critical CSS generation, and more.

ShortPixel’s scope is image optimization only, and if you want performance tooling beyond images, you’ll need a separate solution, which is where their FastPixel plugin comes in.

Ease of Setup

EWWW’s free tier requires no account or API key. You just install, activate, and local compression begins immediately. It’s as frictionless as a WordPress plugin can get. ShortPixel requires an API key even for free use, which adds a small setup step, but in all truth, it’s practically insignificant.

For paid plans, both require an account and both send images to the cloud. ShortPixel has more settings to navigate given the larger feature set, but it also gives you that additional flexibility. EWWW’s interface grows as you enable paid features, though the core stays approachable.

The difference in setup effort becomes much less noticeable once you’re past the free tier.

User Reviews

EWWW holds a 4.8 out of 5 rating on WordPress.org across 1,800+ reviews. ShortPixel sits at 4.5 out of 5 across 800+ reviews.

EWWW reviewers frequently mention easy setup, reliability, quiet background optimization, and the value of extensive free features. ShortPixel’s reviews tend to highlight compression quality, the AI tools, and support responsiveness.

Both scores reflect strong user satisfaction, and in truth, EWWW’s higher rating likely reflects the appeal of its no-friction free tier and the fact that it’s been around for a while longer than ShortPixel rather than any significant performance gain.

ShortPixel or EWWW: Which One Fits Your Site?

ShortPixel is the stronger option if feature depth matters to you. It’s the only plugin of the two with AI tools, it delivers AVIF at every tier including the free one, and its credit-based pricing is well suited to one-time bulk jobs.

If you’re evaluating paid options specifically, ShortPixel’s compression quality lead on JPEGs and its broader feature set make it the more capable tool.

ShortPixel is a strong fit for your WordPress site if:

• You want AI-generated alt text, image metadata, upscaling, or background removal alongside compression.
• You want AVIF support at every plan tier, including the free one.
• You have a large existing library to clean up in one go and want to pay once rather than subscribe.
• You want CDN delivery with the option to step up to dynamic container-aware sizing via Adaptive Images.

EWWW makes more sense if you want to get started without any setup friction at all, or if the performance toolkit bundled into its paid plans reduces the number of separate plugins you need to manage.

Its free tier is genuinely useful for sites that upload occasionally and don’t need lossy compression, and the subscription pricing model suits sites with predictable, high-volume ongoing usage.

EWWW Image Optimizer is a strong alternative if:

• You want to start compressing images immediately with no account or API key.
• You’re on the free tier and keeping image processing on your own server matters, either for privacy or to avoid third-party dependencies.
• You want broader performance tooling (caching, JS/CSS, Critical CSS) bundled with your image plugin.
• CDN bandwidth-based pricing suits your workflow better than per-image credits.

The Bottom Line on ShortPixel and EWWW

The clearest differentiator in this comparison, at least related to image optimization, is AI. ShortPixel has it with alt text, upscaling, and background removal all built into the same plugin. EWWW doesn’t, and for site owners who want image SEO and optimization handled in one place, that gap is decisive.

Compression quality is the second thing worth anchoring on. ShortPixel‘s lead on JPEG compression is backed by multiple independent benchmarks, which matters most for sites with large photo libraries or image-heavy pages where file size directly affects load time.

EWWW is more competitive on PNGs and it bundles the SWIS performance toolkit into every paid plan, which is a genuine advantage for sites that want caching and minification without adding another plugin.

If you’ve decided on ShortPixel and want to get started, this bulk image optimization guide walks through the full setup from compression modes to WebP and AVIF conversion, and how to verify the results in PageSpeed Insights.

Are you currently running either of these plugins? It would be interesting to hear how they’ve compared across different types of sites and hosting setups.