Add Spanish subtitles to X / Twitter videos
Auto-generate Spanish (Español) 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 Spanish well
BurnSub uses OpenAI's Whisper (Whisper code: es),
which has been trained on hundreds of thousands of hours of Spanish speech.
Accuracy on clear-audio Spanish content is typically 92–97%.
Recommended styles for X / Twitter
Step-by-step: Spanish subtitles for X / Twitter
- Open BurnSub. No signup needed — just drop your X / Twitter-format video.
- Pick Spanish from the language dropdown so Whisper transcribes accurately.
- Wait 30–60 seconds. The model runs locally on your GPU (or CPU as fallback).
- Edit captions if needed — every line is editable before burning.
- Pick a style from the recommended X / Twitter presets above.
- Burn + Download. WebCodecs encodes your video on your hardware. No upload at any step.
Frequently asked
Is auto-caption accurate for Spanish?
Whisper's accuracy on Spanish 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 Spanish 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 Spanish, paste the translated SRT back in BurnSub, and burn. Native translation is on the roadmap.