Is convert_to_webp_lossless enabled by default?

Yes. convert_to_webp_lossless is in CoreFilters, the default RewriteLevel, so it runs unless you turn it off with DisableFilters.

How do I turn off convert_to_webp_lossless?

Add ModPagespeedDisableFilters convert_to_webp_lossless on Apache or pagespeed DisableFilters convert_to_webp_lossless; on nginx. On IIS, add pagespeed DisableFilters convert_to_webp_lossless to pagespeed.config.

filter · Image filters

Lossless WebP (convert_to_webp_lossless)

Q: What does the convert_to_webp_lossless filter do?

convert_to_webp_lossless uses lossless WebP encoding instead of lossy. Produces larger files than lossy WebP but preserves every pixel. A CoreFilter, enabled by default through rewrite_images.

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

convert_to_webp_lossless uses lossless WebP encoding instead of lossy. Produces larger files than lossy WebP but preserves every pixel. A CoreFilter, enabled by default through rewrite_images.

When to use it

In CoreFilters, the default RewriteLevel: it runs unless you disable it.
Also switched on by rewrite_images.
Risk rating on these docs: Test first.

Risks

The Image filters page lists no specific risks for this filter. If a page misbehaves with it, DisableFilters convert_to_webp_lossless turns it off for the scope you set it in.

Configuration

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

Apache

ModPagespeedEnableFilters convert_to_webp_lossless

nginx

pagespeed EnableFilters convert_to_webp_lossless;

IIS (pagespeed.config)

pagespeed EnableFilters convert_to_webp_lossless

It is on by default under CoreFilters; to turn it off:

ModPagespeedDisableFilters convert_to_webp_lossless   # Apache
pagespeed DisableFilters convert_to_webp_lossless;   # nginx
pagespeed DisableFilters convert_to_webp_lossless   # IIS

Parameter	Default	Description
`ProgressiveJpegMinBytes`	10240	Minimum JPEG size before converting to progressive
`WebpRecompressionQuality`	80	Quality for lossy WebP conversion
`WebpAnimatedRecompressionQuality`	70	Quality for animated WebP conversion

On the worker

The worker runs its own pipeline, configured by flags. Its equivalent of this filter is the image pipeline transform. Always-on baseline under pagespeed on;; there is no per-transform off switch.

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

Frequently asked questions

What does the convert_to_webp_lossless filter do?: convert_to_webp_lossless uses lossless WebP encoding instead of lossy. Produces larger files than lossy WebP but preserves every pixel. A CoreFilter, enabled by default through rewrite_images.
Is convert_to_webp_lossless enabled by default?: Yes. convert_to_webp_lossless is in CoreFilters, the default RewriteLevel, so it runs unless you turn it off with DisableFilters.
How do I turn off convert_to_webp_lossless?: Add ModPagespeedDisableFilters convert_to_webp_lossless on Apache or pagespeed DisableFilters convert_to_webp_lossless; on nginx. On IIS, add pagespeed DisableFilters convert_to_webp_lossless to pagespeed.config.

convert_gif_to_png — Convert GIF to PNG
convert_jpeg_to_progressive — Progressive JPEG
convert_jpeg_to_webp — Convert JPEG to WebP
convert_png_to_jpeg — Convert PNG to JPEG
convert_to_webp_animated — Animated WebP
convert_jpeg_to_avif — Convert JPEG to AVIF
convert_to_avif_animated — Animated AVIF
convert_to_avif_lossless — Lossless AVIF

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