Support

Playback speed for any video or audio on the web.

Getting started on iPhone or iPad

Open Settings › Apps › Safari › Extensions and turn on pbm.
In Safari, tap the extensions button in the address bar, choose pbm, then Always Allow on Every Website.
Reload the page. A small pill appears over the video.

The pill doesn't appear.: Check the extension is allowed on that site, then reload the page. A tab that was already open when pbm was installed or updated needs a reload before the extension reaches it.
It disappears when I make the video fullscreen on iPhone.: Expected. iPhone's fullscreen button hands playback to Apple's built-in player, which isn't a web page, so nothing on the page can draw over it. A speed you set before going fullscreen still applies. Watching inline keeps the pill available.
I hid the pill and want it back.: If you dragged it off an edge, tap the thin sliver left on that edge. If you switched it off, it's in the extension's settings under On-screen controls.
Reverse playback is choppy.: No browser supports negative playback rates, so reverse is simulated by seeking backwards. Short buffered clips reverse cleanly; long streamed video steps between keyframes instead of playing smoothly. There is no audio during reverse.
Do my settings sync between devices?: In Safari, no — they stay on each device. In Chrome, settings may sync through your Chrome profile; per-site speeds never sync.