Explainroo is a free, open-source tool (by vincentsch) that turns a script into a narrated, animated MP4 explainer video. It runs locally: Kokoro generates the voiceover, Whisper notes when each word is spoken, and a headless Chrome canvas draws the frames with JavaScript. You give the repo to a coding agent like Claude Code, tell it the topic, and it writes the script and scene code and renders the video.

How does Explainroo actually make a video?

The agent writes two files: script.md with the words the voice says, and scenes.js that draws the pictures in JavaScript, with each drawing timed to appear on a specific word. Explainroo then voices the script with Kokoro, uses Whisper to align each word, renders the frames in background Chrome (hand-drawn look via Rough.js, 1,800 Lucide icons, charts, math, step-by-step code, your own screenshots and clips), films each scene with a moving camera, adds its own background music, and outputs an MP4.

Does Explainroo need API keys or a subscription?

No. The voice (Kokoro, 54 voices, 8 languages), the timing (Whisper), and the rendering all run on your own computer with no account or API key required. Optionally you can swap in an ElevenLabs voice or record narration yourself, but the default pipeline is fully local and free.

Who is Explainroo for?

Anyone who needs explainer videos at volume without a motion-design team: product demos, documentation walkthroughs, course lessons, and YouTube explainers. It's especially useful for developers and technical teams who already work with a coding agent, because the whole workflow is 'clone the repo, read AGENTS.md, describe the topic' and the agent does the rest.

Explainroo: Your AI Agent Can Now Make Fully Narrated Explainer Videos from a Prompt

By Prahlad Menon Published 2026-11-06 4 min read

A post from RammCodes has been making the rounds, and it points at something genuinely new: your coding agent can now produce a finished explainer video. Not a storyboard, not a script — a narrated, animated MP4. The tool is Explainroo by vincentsch, and it’s free and open source.

We’ve covered a lot of agent-native tools here. This one stands out because video has, until now, been the one medium that stubbornly resisted the “describe it and get a result” workflow.

What It Is

Explainroo turns a plain-text prompt into a short explainer video where a voice narrates a topic while drawings appear in sync with the words. The whole pipeline runs on your own machine:

Voice — Kokoro, an open voice model, reads the script in English, Spanish, French, Italian, Brazilian Portuguese, Hindi, Japanese, or Mandarin. 54 voices, no account, no API key.
Timing — Whisper listens to the narration and notes exactly when each word is spoken.
Pictures — Chrome runs headless in the background and draws the frames in JavaScript. Lines can look hand-drawn (Rough.js), there are 1,800 Lucide icons, and scenes can show charts, math formulas, step-by-step code, your own screenshots, and video clips.
Camera — a virtual camera films each scene, pushing in on what the voice is describing and pulling back at the end, with little spring animations and motion blur, like a film camera.
Sound — it even generates its own background music per video.

The Interesting Part: It’s Built for Agents

Most video tools want you in an editor. Explainroo wants your coding agent in a terminal. The intended workflow is almost absurdly simple:

Make me a short explainer video about [your topic]. Use explainroo for it: clone https://github.com/vincentsch/explainroo, read its AGENTS.md and follow the steps.

The agent sets up Explainroo, writes two files, and renders the result:

script.md — the words the voice says.
scenes.js — the drawings, in a bit of JavaScript, each keyed to appear on a specific word from the script.

Explainroo does everything else. You get back an MP4. The project notes it works with Claude Code, Codex, Pi, and other coding agents, and currently works best with Claude Code on the strongest models.

Why This Matters

Explainer video has been the expensive corner of content: you need a script, a voiceover, motion graphics, and someone who can sync all three. That’s why most documentation stays as text and most products ship without a demo video. Explainroo collapses that into a prompt.

The use cases write themselves:

Product demos — generate a fresh walkthrough every release, in eight languages, without a studio.
Documentation — turn a tricky concept into a 60-second animated explainer as part of your docs build.
Courses and training — produce lesson videos at the pace you write lessons.
YouTube / marketing — explainer content without a motion-design bottleneck.

Because the drawing layer is just JavaScript on a canvas, it’s inspectable and customizable — the same reason developers trust it that makes designers wary of it. This isn’t going to replace a bespoke, hand-crafted brand film. It’s going to replace the hundred explainer videos that never got made because the effort wasn’t worth it.

The Catch

It’s young, and the quality ceiling depends on the agent driving it and the clarity of your scene descriptions. A hand-drawn-canvas aesthetic is a style, not a universal fit. And “an agent made a video” still needs a human to watch it before it ships — timing glitches, awkward phrasing, and off-topic visuals are exactly the kind of thing that slips through automated generation.

The Takeaway

Explainroo is the first tool we’ve seen that makes “describe a topic, get a narrated animated video” actually work — locally, for free, and driven by the coding agent you already use. If you ship products, docs, or courses, this is worth a weekend: point your agent at the repo and ask it to explain something.

Explore it: github.com/vincentsch/explainroo · explainroo.com.