🔥 BurnSub

Add French subtitles to X / Twitter videos

Auto-generate French (Français) captions and burn them into your X / Twitter video. 100% browser-based, no upload, no watermark, free forever.

16:9 or 1:1 · up to 2:20 · powered by Whisper

Why this works for X / Twitter

X captions need to work in a square or horizontal player at small sizes. High-contrast white-on-pill styles dominate news clips and viral video reposts.

Why Whisper handles French well

BurnSub uses OpenAI's Whisper (Whisper code: fr), which has been trained on hundreds of thousands of hours of French speech. Accuracy on clear-audio French content is typically 92–97%.

Recommended styles for X / Twitter

Step-by-step: French subtitles for X / Twitter

  1. Open BurnSub. No signup needed — just drop your X / Twitter-format video.
  2. Pick French from the language dropdown so Whisper transcribes accurately.
  3. Wait 30–60 seconds. The model runs locally on your GPU (or CPU as fallback).
  4. Edit captions if needed — every line is editable before burning.
  5. Pick a style from the recommended X / Twitter presets above.
  6. Burn + Download. WebCodecs encodes your video on your hardware. No upload at any step.

Frequently asked

Is auto-caption accurate for French?

Whisper's accuracy on French audio is typically 92–97% for clear speech. Background noise, heavy accents, and slang reduce accuracy. Every caption line is editable before burning, so you can fix anything Whisper missed.

Does the X / Twitter algorithm reward burned captions?

Burned captions are read directly by viewers (the words appear on screen) — no AI-detection step required. X / Twitter typically rewards videos with on-screen text because watch-time goes up. Burned subs typically out-perform soft subs on sound-off feeds.

Can I use French subs on a video that's spoken in another language?

Yes — generate the original-language transcript first, then use a translation tool to render it in French, paste the translated SRT back in BurnSub, and burn. Native translation is on the roadmap.

All languages for X / Twitter

French subtitles for other platforms