Pawse

The problem

“3, 2, 1, play” drifts apart within minutes. Tools that re-stream the video lag, or break on DRM.

What I built

• A sync engine that sends only tiny play, pause and seek events over a WebSocket room, with host migration and a rejoin grace period.
• Clock sync with drift correction: followers ignore gaps under 20 ms, nudge playback rate up to 8% below 400 ms, and seek above that.
• Your own file, sent peer to peer over WebRTC in 16 KB chunks. No re-encode, no account.
• YouTube sync through a Chrome extension, plus voice, camera and chat on top.

Stack: React, Node ws relay, WebRTC.

What changed

350 to 6 ms

median gap between two players while playing

13 ms

after a seek

19 ms

with one clock forced 0.5% slow (453 ms and growing without the engine)

13 tests

and zero infrastructure cost

Source: scripts/measure-sync.mjs, 150 ms simulated delay each way, 3 runs, 18 Oct 2026.