What you need before you start
ADee- WordPress 5.8 or newer and PHP 7.4 or newer.
- WebP engine — PHP GD or Imagick. Nearly every host has one.
- AVIF engine — Imagick with the AVIF delegate, GD with AVIF support, or the
avifencbinary (apt install webp libavif-bin).
No AVIF engine? ADee simply skips AVIF and keeps converting WebP — you still get most of the savings, and AVIF switches on automatically once your host adds support.
Convert your first image
Plugins → Add New → Upload Plugin Media Library Convert and every WordPress-generated size.webp
.avif
Bulk-convert the whole media library
One image proves the pipeline works. Real bandwidth savings come from converting everything at once, and ADee gives you three routes.
Route 1 — the dashboard bulk converter (recommended)
ADee → Bulk ConvertRoute 2 — the media library bulk action
Media → Library Convert to WebP/AVIF Bulk actionsRoute 3 — WP-CLI for large libraries
Thousands of images? Run the conversion over SSH instead of the browser so nothing depends on an open tab:
wp adee convert all --limit=100 --skip-existing
screen
tmux
--limit
Turn on auto-convert for new uploads
ADee → Settings Auto-convert on uploadVerify that WebP and AVIF are actually served
serving testPrefer the terminal? Ask for the formats explicitly with curl:
curl -sI -H "Accept: image/avif" https://yoursite.com/wp-content/uploads/2026/11/photo.jpg | grep -i content-type
content-type: image/avif— AVIF is being served. Best case.content-type: image/webp— WebP is being served. Still excellent.image/jpeg— variants exist but the server hands out originals. See the serving-modes guide below.
Quality settings — leave them alone (mostly)
ADee → Settings futurePurge your page cache after a bulk run
purge buttonRelated ADee guides
Frequently asked questions
Does converting change my original images?
wp adee restore all --yes
How long does a bulk conversion take?
It depends on image count, sizes and your engine. On a typical shared host, a few hundred mixed photos convert in minutes. AVIF is slower to encode than WebP, so large libraries with AVIF enabled take longer — the dashboard shows live progress either way.
Can I convert WebP only and skip AVIF?
Yes — switch AVIF off in Settings. ADee also skips AVIF automatically whenever no AVIF engine is available, without touching WebP conversion.
Why is a converted file sometimes bigger than the original?
Heavily optimised sources (already-tiny JPEGs, small PNG logos) occasionally convert to a larger file. ADee detects this and skips such files, so you never end up with a bigger variant than the original.
Do I need to re-convert after changing quality?
Yes. New quality values apply to conversions from that point on. Run the bulk converter again afterwards — existing variants are regenerated with the new settings.
