How it works
Complete the job in three clear steps
- Choose or paste a video and an SRT or VTT caption file.
- Review the timing and create a hard-subtitled MP4.
- Preview or download the result before closing the page.
Private Lucaden subtitle tool
Add Subtitles to Video
Burn SRT or WebVTT captions into a video and export a permanently captioned MP4 locally.
Free to use Your video and subtitle file stay on this device while FFmpeg WebAssembly burns the captions in temporary browser memory.
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Important
Check the result before relying on it
Keep an untouched copy of important source files. Browser processing depends on available device memory, and you should inspect every downloaded result before deleting the original.
Practical details
What this Lucaden tool does
Burn SRT or WebVTT captions into a video and export a permanently captioned MP4 locally.
Lucaden parses the caption track first, writes a normalized temporary SRT beside the video in FFmpeg's in-browser file system, renders the text into the video frames, and removes the temporary files when the job ends.
Included capabilities
- SRT and WebVTT input
- Permanent caption rendering
- Font size, color, outline, and margin controls
- H.264 MP4 output with audio retained
Useful for
- Create captions that work on every player
- Publish a social clip
- Add accessibility text
- Prepare a review copy
Questions
About this tool
Can viewers turn these subtitles off?
No. Hard subtitles become part of the video pixels. Keep the source video and caption file if you may need a different language or style later.
Why can the export take time?
Every video frame must be decoded, captioned, and encoded on your device. Long or high-resolution videos need substantial memory and CPU time.
Open-source foundations
Built transparently
Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.