PixSpeed is deliberately simple, but it lives in the real world — different hosts, different caches, different server software. Here are the seven issues that account for almost every support question, with the fastest fix for each.
| Symptom | Likely cause | Fastest fix |
|---|---|---|
| AVIF badge never appears | No AVIF engine on server | Fix #1 |
| Variants exist but originals are served | Serving config (nginx/cache) | Fix #2 or #3 |
| Old images still load after bulk run | Page cache | Fix #3 |
| GIF looks static | Expected behaviour | Fix #4 |
| Converted image looks worse | Quality setting | Fix #5 |
| Transparency lost | Source file, not the plugin | Fix #6 |
| Variant files left after uninstall | Safety default | Fix #7 |
Fix #1 — No AVIF engine detected
noapt install webp libavif-bin
systemctl reload php8.3-fpm # your PHP version may differ
On shared hosting, ask the host to enable the Imagick AVIF delegate or install libavif-bin. Meanwhile WebP conversion keeps working — PixSpeed degrades gracefully, it never blocks the whole plugin because one format is unavailable.
Fix #2 — Variants exist but browsers get originals (nginx)
map $http_accept
try_files
serving modes explained
nginx -t && systemctl reload nginx
Picture tag
Fix #3 — Old images still loading after a bulk run
Your page cache is serving HTML (or image URLs) generated before the conversion. With the default Picture tag mode this is rare, because the HTML structure does not change. With URL swap mode it is guaranteed — always purge after bulk runs. Either way:
- Use the one-click purge button on the PixSpeed dashboard when FlynCache Purge is active.
- Otherwise run your cache plugin's normal purge — and purge CDN caches if your CDN caches HTML or images aggressively.
- Hard-refresh your browser (Ctrl+Shift+R) — sometimes the only stale copy is your own.
Fix #4 — Animated GIFs: what to expect
largerFix #5 — A converted image looks worse than the original
SettingsFix #6 — Transparency problems in PNGs
WebP and AVIF both support full alpha transparency, and PixSpeed preserves it — if a PNG's transparent background suddenly looks wrong, check the source: transparency flattened before upload cannot be recovered by any converter. Also verify the theme is not placing the image on a coloured background via CSS. If a specific file still misbehaves, restore that single image and re-convert it at higher quality — and if it persists, report it via digitalwasim.com with the original file attached.
Fix #7 — Variant files remain after uninstalling
keeps variant filesdefine('WAC_DELETE_FILES', true);
Still stuck?
serving modes guide installation guide digitalwasim.comFrequently asked questions
How do I check whether variants are being served?
Use the serving test button on the PixSpeed dashboard — it requests one of your converted images with a modern browser's Accept header and reports exactly which format came back and how much smaller it was.
Is it safe to delete the plugin to start over?
Deactivating and deleting removes PixSpeed's settings and database records but leaves variant files on disk by default. To also delete those files, define WAC_DELETE_FILES as true in wp-config.php before deleting — or restore everything first.
Where do I report a bug or ask a question?
Reach the developer via digitalwasim.com. PixSpeed is maintained by Wasim Akram, who also maintains FlynCache Purge — support articles for both live on this site.
