When you compare Smush vs ShortPixel vs EWWW, all three compress your images and can create WebP versions; the real differences are where the work happens and how you pay. Choose EWWW Image Optimizer if you want free, unlimited compression on your own server, ShortPixel if you want the processing done in the cloud with flexible credits, and Smush if you want the simplest free setup and your images are under 5 MB. Whichever you pick, keep the main image at the top of each page out of lazy loading.
In this article
Smush vs ShortPixel vs EWWW: what is the difference?
The biggest difference is where your images are processed: Smush and ShortPixel send them to cloud servers, while EWWW's free mode compresses them on your own web server. Prices below are at the time of writing (October 2026).
| Smush | ShortPixel | EWWW Image Optimizer | |
|---|---|---|---|
| Where images are processed | Smush's cloud servers | ShortPixel's cloud | Your server (free), EWWW's cloud (paid) |
| Free tier | Lossless and lossy, images up to 5 MB | 100 credits a month | Unlimited lossless compression |
| WebP and AVIF | Pro only | Every plan, one extra credit per version | WebP free, AVIF through paid Easy IO |
| Image CDN | Pro, 119 locations | Included, credit-based or 500 GB a month on Unlimited | Easy IO, paid |
| Keeps originals | Optional backup | Optional local backup | Local backups free, 30-day cloud backups paid |
| Paid plans from | $50 a year for 1 site | $10.99 a month (unlimited) or $19.99 one-time | $8 a month or $80 a year, unlimited sites |
What do you get with Smush free, and what does Smush Pro add?
Smush free, made by WPMU DEV, compresses new uploads and your existing library automatically with no cap on bulk optimization, but it skips any image larger than 5 MB.
It offers three compression levels: Basic (lossless), Super (lossy, free once you connect a free WPMU DEV account) and Ultra, which WPMU DEV says compresses five times more than Super and is Pro only. Images are sent over HTTPS to Smush's cloud servers, compressed and returned, so the work does not run on your host. Lazy loading is included free.
Smush Pro adds Ultra compression, WebP and AVIF conversion (served from your own server or the Smush CDN), a 119-location CDN, automatic resizing, missing image dimensions, preloading of the main image and a 256 MB size limit. Pro Basic costs $50 a year for one site with 50 GB of CDN traffic; Pro Standard is $75 for 3 sites and Pro Plus $100 for 10. The full WPMU DEV membership (all its plugins, unlimited sites) lists at $9.99 a month, discounted to $4.99 for the first three months at the time of writing. All plans carry a 30-day money-back guarantee.
How does ShortPixel's credit pricing work?
ShortPixel uses one credit each time it shrinks an image or thumbnail by at least 5%, and every account gets 100 free credits a month. The catch is that WordPress makes several sizes of each upload, each size costs a credit, and every WebP or AVIF copy costs another. ShortPixel's own example: one image with eight thumbnails and WebP versions uses 18 credits, so the free allowance covers only a few uploads.
All processing happens in ShortPixel's cloud, so your host does no heavy lifting, but the plugin does not work on a local copy of a site. You choose Lossy, Glossy (a high-quality lossy mode for photographers and product photos) or Lossless, originals can be backed up locally, and it compresses PDFs as well. WebP and AVIF can be delivered with picture tags, server rewrite rules or ShortPixel's CDN; on credit plans, CDN traffic also draws on your credits.
Paid options at the time of writing:
- Unlimited: $10.99 a month or $99.90 a year, unlimited sites and images, 500 GB of CDN traffic a month.
- One-time packages: $19.99 for 30,000 credits, up to $99 for 250,000. One-time credits never expire; monthly credits expire after 30 days.
ShortPixel suggests a one-time package to process an existing library, then a monthly plan for new uploads.
Is EWWW Image Optimizer really free and unlimited?
Yes. In its free mode EWWW compresses as many images as you like, of any size, using tools that run on your own web server. That needs the PHP exec() function, which some hosts switch off; on those hosts EWWW offers free, unlimited lossless compression for JPGs through its cloud instead.
Free mode is lossless, and EWWW's own figure for it is an average saving of 8%. It also creates WebP copies for free (delivered with server rewrite rules, a JavaScript rewriter or picture tags), resizes images on upload, keeps local backups and lazy loads images, with an Above the Fold setting that skips the first images on a page.
Paid plans add lossy compression through the Compress API, AVIF, PDF compression and the Easy IO CDN (formerly ExactDN). Easy IO compresses, resizes, converts and lazy loads images on the fly from EWWW's servers and leaves your original files untouched, so it speeds delivery but does not save disk space. Every plan includes the API and Easy IO on unlimited sites. Standard costs $8 a month or $80 a year at the time of writing, with 50 GB of CDN bandwidth, 25,000 premium compression credits a month and the SWIS Performance plugin; Growth ($16 a month) and Infinite ($32) add bandwidth and credits.
Free mode runs on your own server, so on a small hosting plan schedule big bulk jobs for quiet times.
Should you use lossy or lossless compression?
Use lossy (or ShortPixel's Glossy) for photographs, and keep lossless for logos, screenshots and graphics with text. Lossless shrinks a file without changing a single pixel, so savings are modest. Lossy discards detail the eye rarely notices and saves far more. Test a few images before a bulk run, and keep backups switched on so you can restore an original.
Do you need WebP and AVIF images?
They help, but conversion is only half the job: the plugin also has to serve the new format to browsers that support it. WordPress.org puts WebP at around 30% smaller than an equivalent JPEG or PNG on average. WordPress has accepted WebP uploads since version 5.8 and AVIF since 6.5, but it does not convert your JPEGs for you.
If your plugin delivers WebP through rewrite rules and your server runs Nginx, your host has to add them. If you use a CDN such as Cloudflare, purge its cache after a bulk run so visitors get the new files.
Does WordPress already lazy load images?
Yes. Since WordPress 5.5, core adds loading="lazy" to images that have width and height set, and 5.7 extended that to iframes. WordPress 5.9 stopped lazy loading the first image in the content, and 6.3 began marking the image most likely to be the main one with fetchpriority="high", telling the browser to fetch it first. A typical small business site gets sensible lazy loading without any plugin.
Why shouldn't the hero image be lazy-loaded?
Because the hero is usually the Largest Contentful Paint (LCP) element, and lazy loading it makes the browser wait before fetching it. Google counts an LCP of 2.5 seconds or less as good, and its guidance is plain: do not lazy load images that are likely to be on screen when the page opens.
Many page builders set a hero as a CSS background image, which can be the LCP element too. WordPress's lazy loading does not touch it, but some plugins lazy load background images, so exclude the hero in your plugin's settings. To find your LCP element, run the page through PageSpeed Insights.
Should you resize images before you upload them?
Yes. An optimizer reduces file size, but it cannot fix a photo that is several times larger than the space it fills. Since version 5.3, WordPress scales any upload wider or taller than 2,560 pixels and keeps the original on the server as well.
Exporting photos at the size your layout actually uses saves disk space and upload time, and keeps large camera originals under Smush's 5 MB free limit.
When is an image plugin doing a job twice?
When it switches on lazy loading, WebP delivery or a CDN that WordPress, your host or your caching plugin already provides. Smush's own documentation advises turning lazy load on in only one plugin at a time. A caching plugin such as WP Rocket lazy loads and prioritizes the main image, but it does not compress images, so pair it with one optimizer and choose which one lazy loads.
Run one image optimizer, not two. If all you want is WebP or AVIF versions of new uploads, the WordPress Performance Team's free Modern Image Formats plugin does that.
Which image optimizer should you choose?
- Choose EWWW if your host allows local compression and you want unlimited free compression, or one subscription that covers image CDN delivery for many sites.
- Choose ShortPixel if you want the work off your server, a choice of lossy, Glossy or lossless, PDF compression, or one-time credits that never expire.
- Choose Smush if you want the simplest setup, your images are under 5 MB, or you already use WPMU DEV's plugins.
Whatever you choose, test on a staging copy and check your LCP before and after. If you would rather hand it off, WP Resolve's Speed Optimization is a one-off $399 Core Web Vitals pass with before-and-after numbers.
Not sure where your site stands? The free site health check covers your updates, backups, security and speed, or you can text WP Resolve at (916) 209-0917.
Frequently asked questions
Is Smush better than ShortPixel?
Neither wins outright. Smush is simpler and its free version has no monthly image limit, while ShortPixel offers more compression and delivery options but charges a credit for every image size and format it creates.
Is EWWW Image Optimizer free?
Yes. Its free mode compresses unlimited images losslessly on your own server and creates WebP copies. Lossy compression, AVIF and the Easy IO CDN are paid, from $8 a month at the time of writing (October 2026).
Do I still need an image optimizer if WordPress lazy loads images?
Usually, yes. WordPress lazy loads images and prioritizes the main one, but it does not compress your uploads or convert JPEGs to WebP or AVIF.
Should I lazy load my hero image?
No. The hero is usually the Largest Contentful Paint element, and lazy loading it delays the most important image on the page. WordPress skips the first content image for this reason, so make sure your plugins do too.
Does ShortPixel charge credits for thumbnails?
Yes. Each thumbnail it shrinks by at least 5% uses a credit, and each WebP or AVIF version uses another.
Can I use two image optimization plugins at once?
It is best not to. Run one optimizer, and let only one tool handle lazy loading, whether that is WordPress itself, your image plugin or your caching plugin.
