DynamicSpeed for YouTube — damjanmiklos

DynamicSpeed keeps YouTube at your listening pace.

Set a target words-per-minute (for example 165). The extension measures how fast the speaker is talking from caption timings, then raises or lowers playback speed so speech stays near that target. Slow explainers move along. Fast talkers ease off. You are not stuck at one fixed multiplier for every video.

HOW IT WORKS
• Reads timed captions for the video (auto-generated or creator-uploaded)
• Estimates spoken WPM from those timings
• Sets YouTube’s playback rate ≈ target WPM ÷ spoken WPM, clamped to your min/max
• Smooths changes so speed does not jump around on noisy captions
• Holds your default speed while captions are still loading

Captions are required. If a video has no captions, DynamicSpeed stays on your default speed instead of guessing. It may briefly turn YouTube captions on so timings can be downloaded, then restores whatever you had before (on or off). On-screen captions are not left visible if you had them off.

FEATURES
• Target WPM, plus min / max / default speed
• Player chip next to YouTube’s settings gear (current rate; click to toggle)
• Toolbar popup with live WPM and speed
• Per-channel and per-video disable
• Optional b-roll acceleration for long pauses and [Music] tags
• Ignores ads and official Music videos by default
• Works on YouTube Shorts (can be turned off)
• Keyboard shortcuts (toggle, WPM up/down)
• Export/import settings as JSON
• Open source

PRIVACY
Nothing is uploaded. There is no account, no analytics, and no DynamicSpeed server. Settings and a small local caption cache stay in this browser. Captions are fetched from YouTube the same way the player already does, then parsed on your device.

Open source: https://github.com/damjanmiklos/dynamicspeed-for-youtube
Bugs: https://github.com/damjanmiklos/dynamicspeed-for-youtube/issues