Hardcode Subtitles Tool
Burn an SRT subtitle file permanently into a video in your browser.
Runs in your browser Your input never leaves your device.
About this tool
Pick a video and a subtitle file, and the tool burns the text permanently into the picture using ffmpeg's subtitles filter in WebAssembly, then outputs an MP4. Everything runs in your browser and neither file is uploaded. Style is whatever the default is: there are no controls for color, size or position. Because the video must be re-encoded, expect a long wait and some quality loss, and long or high-resolution videos may run out of memory. Plain SRT files are the safe choice. The first run downloads the ffmpeg engine (about 25 MB) from a CDN, which can take from a few seconds to a minute on a slow connection; later runs on the same page reuse it.
How to use it
- Choose the video as File 1.
- Choose your .srt subtitle file as the second file.
- Press Process and wait; re-encoding is slow.
- Preview the result and press Download (output.mp4).
Common problems
- Processing fails with a subtitles message
- The in-browser ffmpeg build may lack the subtitle renderer or fonts. This is a known limit; try a short clip with a plain SRT file.
- An .ass file does not work
- The file is always read as SRT, so ASS styling is not applied. Convert it to SRT first.
- Subtitles are out of sync
- Timing comes from the file. Fix the timestamps in the SRT, as this tool has no offset setting.