Is experiment_collect_mob_image_info enabled by default?

No. experiment_collect_mob_image_info is in the dangerous set, which no RewriteLevel enables, not even AllFilters. Enable it by name, for testing and measurement only.

How do I enable experiment_collect_mob_image_info on Apache and nginx?

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

filter · Image filters

Collect mobile image info (experiment_collect_mob_image_info)

Category:: Image
CoreFilters:: No
OptimizeForBandwidth:: No
Risk:: Dangerous set

Collects image information for the retired page-mobilization experiment. In the dangerous set, which RewriteLevel AllFilters never enables; not for production.

When to use it

In the dangerous set: no RewriteLevel enables it, not even AllFilters. It exists for testing and measurement, not for production traffic.
Risk rating on these docs: Dangerous.

Risks

The Image filters page lists no specific risks for this filter. If a page misbehaves with it, DisableFilters experiment_collect_mob_image_info 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 experiment_collect_mob_image_info

nginx

pagespeed EnableFilters experiment_collect_mob_image_info;

IIS (pagespeed.config)

pagespeed EnableFilters experiment_collect_mob_image_info

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

Frequently asked questions

What does the experiment_collect_mob_image_info filter do?: Collects image information for the retired page-mobilization experiment. In the dangerous set, which RewriteLevel AllFilters never enables; not for production.
Is experiment_collect_mob_image_info enabled by default?: No. experiment_collect_mob_image_info is in the dangerous set, which no RewriteLevel enables, not even AllFilters. Enable it by name, for testing and measurement only.
How do I enable experiment_collect_mob_image_info on Apache and nginx?: Add ModPagespeedEnableFilters experiment_collect_mob_image_info on Apache or pagespeed EnableFilters experiment_collect_mob_image_info; on nginx. On IIS, add pagespeed EnableFilters experiment_collect_mob_image_info to pagespeed.config.

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

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