Controlling the use of beacons

The lazyload_images, inline_preview_images, and inline_images filters, use a beacon to collect information about the rewritten page so as to optimize the rewriting process. The beacon is a POST request sent back by JavaScript inserted into the page by the filter. The use of this beacon is on by default but it can be disabled using:

pagespeed CriticalImagesBeaconEnabled false

If you disable image beacons but enable filters that use them, the filters will work but not as well as when beacons are enabled.

This directive can be used in all scopes including location-specific configuration sections.