Is convert_jpeg_to_avif enabled by default?

No. convert_jpeg_to_avif is not in CoreFilters, the default RewriteLevel; it runs only when you enable it by name with EnableFilters.

How do I enable convert_jpeg_to_avif on Apache and nginx?

Add ModPagespeedEnableFilters convert_jpeg_to_avif on Apache or pagespeed EnableFilters convert_jpeg_to_avif; on nginx. On IIS, add pagespeed EnableFilters convert_jpeg_to_avif to pagespeed.config.

filter · Image filters

Convert JPEG to AVIF (convert_jpeg_to_avif)

Q: What does the convert_jpeg_to_avif filter do?

convert_jpeg_to_avif encodes photographic JPEG sources as AVIF.

Category:: Image
CoreFilters:: No
OptimizeForBandwidth:: No
Risk:: Test first

convert_jpeg_to_avif encodes photographic JPEG sources as AVIF.

How it works

Four filters transcode images to AVIF.

All four are opt-in. They sit outside rewrite_images and outside the CoreFilters set, so enabling rewrite_images alone produces no AVIF output — you have to name the AVIF filters you want.

AVIF is served only when the request advertises Accept: image/avif. There is no User-Agent sniffing. A client that does not advertise AVIF falls through the existing format order unchanged. The cache key folds in the client’s AVIF capability, so variants are stored and served per capability exactly as WebP variants are.

The AV1 encoder is statically linked into the module. There is no separate package or codec library to install.

Caveat: `RewriteLevel AllFilters` enables all four

“Opt-in” holds for filters you name explicitly. The four AVIF filters are not in the dangerous-filter set, so RewriteLevel AllFilters switches all of them on. If you run AllFilters, you are running the AVIF filters whether or not you listed them.

When to use it

Not in CoreFilters: it runs only when you enable it by name.
Risk rating on these docs: Test first.

Risks

An AVIF candidate costs a full extra decode and encode per image. The module encodes an AVIF candidate and keeps it only if it beats the WebP or optimized-original candidate. Each candidate is produced from its own decode; the decode is not shared between formats. AV1 encoding is also slower than WebP encoding at comparable quality, so enabling AVIF measurably raises the CPU cost of the first rewrite of every image. Watch ImageMaxRewritesAtOnce and the rewrite deadline on busy origins.
Pick-smaller means some of that work is discarded. When the AVIF candidate is not smaller, it is dropped and the existing variant is served. The CPU is spent either way.
Images with C2PA content credentials are not converted. A source carrying a C2PA manifest is left alone by all four filters, so its provenance chain survives the pipeline.
Delivery depends on the Accept header reaching the module. As with convert_jpeg_to_webp, a CDN or proxy that rewrites Accept or ignores Vary: Accept can cross-serve formats. Test with your CDN configuration before rolling out.

Configuration

Enable it in the module configuration, at server, virtual-host or location scope:

Apache

ModPagespeedEnableFilters convert_jpeg_to_avif

nginx

pagespeed EnableFilters convert_jpeg_to_avif;

IIS (pagespeed.config)

pagespeed EnableFilters convert_jpeg_to_avif

On IIS, use the same filter names in pagespeed.config without the trailing semicolon — see IIS configuration.

Parameter	Default	Description
`AvifRecompressionQuality`	60	AVIF quality level; -1 uses `ImageRecompressionQuality`
`AvifRecompressionQualityForSmallScreens`	50	AVIF quality for small-screen clients; -1 uses `AvifRecompressionQuality`
`AvifAnimatedRecompressionQuality`	50	Quality for animated AVIF output
`AvifQualityForSaveData`	45	AVIF quality for clients sending `Save-Data: on`
`AvifTimeoutMs`	5000	Wall-clock budget for one AVIF encode; the encode is abandoned when it is exceeded

These mirror the Webp* quality parameters: a value of -1 falls back to the more general setting, so you can set ImageRecompressionQuality alone and let AVIF follow it.

AvifTimeoutMs exists because AV1 still-image encoding is materially slower than WebP. The budget stops one expensive image from occupying a rewrite slot indefinitely; when it is hit the AVIF candidate is abandoned and the existing WebP or optimized-original output is served, so a timeout costs CPU but never a broken image. Raise it if large photographic sources are being skipped, lower it if AVIF encodes are crowding out other rewrites.

Scoping, ForbidFilters and the thresholds filters read: Choosing filters .

Live example

Re-encodes photographic JPEGs as AVIF for browsers that accept it.

Measured on the demo page, original against optimized:

Total bytes

240.9 KB → 10.2 KB −96%

See the before and after, with the source diff →

Frequently asked questions

What does the convert_jpeg_to_avif filter do?: convert_jpeg_to_avif encodes photographic JPEG sources as AVIF.
Is convert_jpeg_to_avif enabled by default?: No. convert_jpeg_to_avif is not in CoreFilters, the default RewriteLevel; it runs only when you enable it by name with EnableFilters.
How do I enable convert_jpeg_to_avif on Apache and nginx?: Add ModPagespeedEnableFilters convert_jpeg_to_avif on Apache or pagespeed EnableFilters convert_jpeg_to_avif; on nginx. On IIS, add pagespeed EnableFilters convert_jpeg_to_avif to pagespeed.config.

convert_jpeg_to_webp — Convert JPEG to WebP
convert_to_avif_lossless — Lossless AVIF
rewrite_images — Optimize images
convert_to_avif_animated — Animated AVIF
recompress_avif — Recompress AVIF
convert_gif_to_png — Convert GIF to PNG
convert_jpeg_to_progressive — Progressive JPEG
convert_png_to_jpeg — Convert PNG to JPEG

This page is drawn from the convert_jpeg_to_avif entry on Image filters. Every filter in one table: PageSpeed filters.