Burn subtitles into video
Generate the correct ffmpeg command to burn SRT or ASS subtitles permanently into your MP4. Copy, paste in your terminal, run.
How it works
ffmpeg.wasm is too heavy (30+ MB per session) for a one-off subtitle burn. The honest move is to give you the exact command to run locally on your machine. The generator below assembles a tested ffmpeg invocation: -vf subtitles=...:force_style=FontSize=N for hard-coded burn-in. Audio passes through unchanged via -c:a copy.
FAQ
Why generate a command instead of doing it in-browser?
Burning subtitles requires ffmpeg.wasm which is a 30 MB download per session. For a one-off subtitle burn, running ffmpeg locally takes 5 minutes and produces better quality. This page generates the correct command for you.
What subtitle formats does ffmpeg support?
SRT (most common), ASS / SSA (with styling), WebVTT, Sub Station Alpha. The generated command uses the subtitles filter which auto-detects format.
Can I customise the styling?
For SRT - no, styling is fixed. For ASS - yes, the .ass file controls font, colour, position. The generated command pipes both into ffmpeg.
How do I install ffmpeg?
macOS: brew install ffmpeg. Ubuntu/Debian: sudo apt install ffmpeg. Windows: download from ffmpeg.org or scoop install ffmpeg. The generated command works on all three.
What is the difference between hard and soft subs?
Hard subs are burned into the video pixels - cannot be turned off, work everywhere. Soft subs are a separate track inside the MP4/MKV - can be toggled off, may not display on all players. This tool generates hard subs.