A WordPress image optimization plugin compresses and resizes your images, and most can convert them to WebP or AVIF so pages load faster. They differ on which formats they name and how they handle the work. Ten free plugins follow in no particular order, with their directory numbers as of Oct 2026.
Every photo you upload can slow a page down, and an image plugin's job is to make them lighter without making them look worse. That means compressing new uploads automatically, working through the old ones in bulk, and serving a newer, lighter format where it can.
The ten plugins below are listed alphabetically and in no particular order, each described from its own WordPress.org directory page. Images are one part of site speed, and my guide on how to speed up your website covers the rest.
Image optimization plugins side by side
Each plugin here is free in the WordPress.org plugin directory, as of Oct 2026, so the free plan column reads Yes. Some limit how much they'll optimise for free and sell larger allowances on their own sites, so check the plugin's page before you bulk optimise a big media library.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Converter for Media | WordPress plugin | WebP and AVIF conversion | Yes |
| EWWW Image Optimizer | WordPress plugin | WebP, AVIF and lazy load | Yes |
| Imagify | WordPress plugin | One-click compress, resize, WebP and AVIF | Yes |
| Optimole | WordPress plugin | Bulk compression and lazy loading | Yes |
| reSmush.it | WordPress plugin | A free image compressor | Yes |
| Robin Image Optimizer | WordPress plugin | Unlimited automatic optimization | Yes |
| ShortPixel Image Optimizer | WordPress plugin | Images and PDFs, WebP and AVIF | Yes |
| Smush | WordPress plugin | Compression, lazy load, WebP and AVIF | Yes |
| TinyPNG Image Optimization | WordPress plugin | JPEG, PNG and WebP compression | Yes |
| WPvivid Image Optimization | WordPress plugin | Bulk compress, resize and lazy load | Yes |
Ten plugins that make images lighter
Converter for Media
Best for: Serving WebP and AVIF versions of your images instead of the standard formats, to speed up the site.
EWWW Image Optimizer
Best for: All-round optimisation with WebP, AVIF and lazy load, set to optimise images automatically as you go.
Imagify
Best for: Setting up image optimisation in one click to compress, resize and convert images to WebP or AVIF.
Optimole
Best for: Automatic bulk compression, lazy loading and WebP or AVIF conversion, served through a CloudFront image CDN.
reSmush.it
Best for: A free image compressor and optimizer that keeps things simple while improving site speed and SEO.
Robin Image Optimizer
Best for: Unlimited automatic image optimisation, with compression and WebP conversion that keeps image quality intact.
ShortPixel Image Optimizer
Best for: Compressing images and PDFs, converting to WebP and AVIF, and generating SEO-friendly file names with AI.
Smush
Best for: Compression, lazy load and WebP or AVIF serving in one plugin, with a global image CDN to speed things up.
TinyPNG Image Optimization
Best for: Automatic JPEG, PNG and WebP compression through the TinyPNG service, for sites that don't need AVIF.
WPvivid Image Optimization
Best for: Bulk compressing and resizing images, lazy loading them, and auto-resizing new uploads as they arrive.
The speed target these plugins serve
web.dev's guide to optimizing Largest Contentful Paint says sites should strive to have an LCP of 2.5 seconds or less for at least 75% of page visits. LCP is the moment the biggest thing on screen finishes loading, and on most pages that's an image.
That's why image weight matters so much. A plugin that compresses and resizes on upload, lazy loads images further down the page and serves a lighter format can bring that moment forward without you touching a line of code.
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WebP, AVIF and what Google can index
Google Search Central's image SEO best practices say Google Search supports images in the src attribute in these formats: BMP, GIF, JPEG, PNG, WebP, SVG and AVIF. So converting to WebP or AVIF with a plugin keeps you within what Google can index.
AVIF support isn't universal in the descriptions, though. Smush, EWWW, ShortPixel and Optimole name AVIF, as do both plugins named in the ratings line below, while TinyPNG's directory description lists JPEG, PNG and WebP only. If AVIF matters to you, read the description before you install.
Ratings, as of Oct 2026, run from 98/100 (Converter for Media, 500,000+ installs) down to 86/100, shared by Imagify (900,000+ installs, last updated 7 Sep 2026) and two smaller plugins. A big install count doesn't guarantee a happy user base, so read both numbers.
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Questions to ask before you bulk optimise
- Does it optimise new uploads automatically, as well as the images already in the library?
- Which formats does it convert to: WebP, AVIF or both?
- Does it lazy load images, or will you need something else for that?
- Does it resize oversized images when they're uploaded?
- Does it serve images from a CDN, and are you happy with that?
- Does it handle PDFs as well as images?
Do you make a WordPress image optimization plugin? Tool makers can ask to be considered for a featured place on this list.
My plain advice on image plugins
Choose one plugin that compresses on upload, converts to the format you want and can work through your old images in bulk. Then check a few key pages afterwards, because a lighter image that looks blurry is no win. Speed is the goal, and the 2.5 second LCP target is the one to measure against.
Good file names and alt text still matter once the files are lighter, and my guide to alt text mistakes to avoid covers the words side.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
What does a WordPress image optimization plugin do?
It compresses and resizes images, and many convert them to lighter formats such as WebP or AVIF. Some add lazy loading or an image CDN as well.
Can Google index WebP and AVIF images?
Yes. Google Search supports BMP, GIF, JPEG, PNG, WebP, SVG and AVIF images in the src attribute. Check which formats your plugin names before you choose.
Do image plugins help Core Web Vitals?
They can. web.dev says sites should aim for an LCP of 2.5 seconds or less for at least 75% of page visits, and image weight is often a big part of that.
Can I optimise images I've already uploaded?
Several plugins here name bulk optimization, which works through your existing media library as well as new uploads.
Are these image optimization plugins free?
All ten are free plugins in the WordPress.org plugin directory, as of Oct 2026, though some limit free use, so check the plugin page.
