vincentsch / explainroo

Explainer videos made by your AI agent. 
 Free and open source. The voice, the timing and the rendering run on your computer.
 Website  · 
 Example videos  · 
 Docs  · 
 AGENTS.md 
https://github.com/user-attachments/assets/6dd5dc32-c975-4e0e-8cd4-2ef3ccc11e61
 A coding agent made this video with explainroo. You can also watch it on explainroo.com . 
## News
- **Oct 20, 2026**: explainroo 0.4.1 keeps arrow and chart labels whole while a shot holds.
- **Oct 15, 2026**: explainroo 0.4 films each scene with a camera that follows the narration.
- **Oct 13, 2026**: explainroo 0.3 narrates in Japanese and Mandarin Chinese, and adds the editorial look.
- **Oct 13, 2026**: explainroo 0.2 adds five more languages, other voices and video clips.
All news is on explainroo.com/news.
## Make a video
> [!TIP]
> **Give your coding agent this repo and tell it what the video should explain.**
> It works with Claude Code, Codex, Pi and other coding agents. Right now it
> works best with Claude Code and Opus 5.5.
Copy this into your agent and put your topic in place of the brackets:
 [code] 
The agent sets up explainroo, makes the video and checks it. You get an MP4
file.
## How does it work?
An explainer video is a short video where a voice explains a topic and
drawings appear while it speaks. For explainroo, the agent writes two files.
`script.md` has the words the voice says. `scenes.js` draws the pictures with
a bit of JavaScript, and each drawing can appear on a word from the script.
explainroo does the rest:
- **Voice.** Kokoro, an open
 voice model, reads the script aloud in English, Spanish, French, Italian,
 Brazilian Portuguese, Hindi, Japanese or Mandarin Chinese. It has 54 voices
 and needs no account or API key. You can also use an ElevenLabs voice or
 record the narration yourself.
- **Timing.** Whisper listens to the
 narration and notes when each word is spoken.
- **Pictures.** Chrome runs in the background and draws the frames. The lines
 can look hand drawn (Rough.js), and there are 1,800
 icons from Lucide. A scene can also show charts, math
 formulas, code that changes step by step, your own screenshots and video
 clips such as screen recordings.
- **Camera.** A camera films each scene. It moves in on what the voice talks
 about when there is time, and pulls back at the end so the last frame shows
 the whole idea. Cards and labels are never cut in half while a shot holds.
 Things arrive with a little spring, and the final video has motion blur,
 like a film camera.
- **Sound.** explainroo makes its own background music for each video and
 adds small sound effects. The music gets quieter while the voice speaks.
- **File.** ffmpeg puts it all together into an MP4, with subtitle files,
 YouTube chapters and a cover image.
An agent can't watch a video, so explainroo gives it other ways to check its
work. It saves stills of the scenes and a sheet of small frames for the whole
video. A layout check finds text that is cut off or overlaps, and a speech
c