Best AI script writers for documentaries, and the master prompt that gets a usable draft

Claude, ChatGPT and Gemini compared for documentary scripts, with the structured prompt that produces a voice-led draft instead of an essay, and the rewrite rules that finish it.

An LLM can draft a documentary script in a minute. Whether the draft is usable depends almost entirely on the prompt and on what you do after. Here's the comparison and the prompt.

The models

All three produce essays by default. The prompt has to force a voice-led film shape.

The master prompt

Paste this, then your topic:

Write the narration for a 12-minute documentary about [TOPIC]. Write for a spoken voice: sentences of 8–15 words, one idea per sentence, no adjectives that don't add information. Structure it as: (1) a cold open of 60–80 words that starts with the single most surprising fact, with no introduction; (2) one sentence that poses the question the film answers; (3) four chapters of 300–350 words each, each answering part of the question, each ending on a line that raises the next; (4) a turn of 100 words that reverses what the audience assumed; (5) a landing of 60 words that says what it means and stops, without summarising. Mark a line break wherever the narrator should pause. Put every date and number in its own short sentence. Do not describe what's on screen. Output only the narration.

Then, per chapter, ask for a list of the claims and the sources you should verify.

The rewrite that makes it yours

1. Read it aloud. Cut every sentence you stumble on.
2. Replace generic openers ("Throughout history...") with a concrete image.
3. Check every fact; models invent dates and quotes.
4. Add one specific detail per chapter that only research gives you.
5. Shorten the landing again.

See how to write documentary narration.

From script to film

The script is the spine. In Glisse it becomes the voice (performed, word-timed) and the AI adapts an editor's template to it: licensed footage per line, maps for the places and years, and a cut anchored to the narration. Change a paragraph and the film re-cuts. The prompt above is written for that: dates on their own lines become cut points; pauses become card moments.

FAQ

Which AI is best for writing documentary scripts?

Claude for structure and long scripts, ChatGPT for fast hooks, Gemini for research-adjacent drafts. The prompt matters more than the model.

How long should an AI documentary script be?

About 130 words per finished minute: 1,500–1,600 words for 12 minutes.

Can AI write a whole documentary?

It can draft the narration. The facts need verification and the sentences need rewriting for the ear; the film itself needs footage, maps, voice and an editor's cut.