Image Resizer documentation

WordPress keeps the 6000-pixel photo somebody dragged in from a phone, and then serves it. Image Resizer caps dimensions on upload, converts to modern formats, and can go back and fix everything already in the library.

User guide

Getting starteddraftInstall the free plugin, set a maximum width and height, and check that the next upload actually shrank.Image Resizer does one thing on install: it stops WordPress keeping the 6000-pixel photograph somebody dragged in from a phone. Everything…
Bulk regenerateplaceholderFix a library that is already full of oversized images, without a PHP timeout costing you the whole run.Capping new uploads solves tomorrow's problem. The library you already have is today's, and on a site with ten years of posts it is usually…
WebP, AVIF and JPEGWhich image format to serve, what each one costs to produce, and why the original is always kept as a fallback.This page is about the formats themselves rather than about our plugin, and none of it will change when the software ships. If you are…

For developers

Developer referenceplaceholderWhere the plugin will let you intervene — filters, actions and WP-CLI — and what is deliberately not extensible.Every hook name, argument and return type on this page is a placeholder. They are written out because the shape of the extension surface is…

Elsewhere

Image Resizer changelog — every published release, from the release record.
Image Resizer overview — what it does, and what Pro adds.