PymDrop by artsntech

PymDrop reduces bandwidth usage by intercepting .jpg, .jpeg, and .png image requests before they are downloaded, redirecting them to a proxy server that re-encodes them to WebP at a configurable quality. It also blocks trackers, ads, and telemetry domains.

The extension includes a whitelist to disable processing on specific sites, and a floating button for quick access to that whitelist. It is designed for both Chrome and Firefox.

Note: A self-hosted proxy server (Go) is required for image compression to work. Instructions for setting it up are provided in the extension's settings page.