No upload · No size limit · No watermark · No signup
Add subtitles to video online — free, private, no upload
Burn SRT or VTT captions permanently into your clip so they show on every player and every social platform. Everything runs locally in your browser — load your subtitle file, choose where the captions sit and how big they are, preview, then download the hardcoded video. The original audio is kept.
How it works
- Drop a video file. It stays on your device the whole time.
- Load a matching .srt or .vtt subtitle file — the tool shows how many captions it found.
- Pick the caption position, text size and whether to draw a dark band behind the text.
- Press burn in subtitles and watch the progress bar.
- Preview the result and download it — an MP4 with the captions hardcoded in.
Frequently asked questions
What's the difference between burned-in and soft subtitles?
Burned-in (hardcoded) subtitles are painted directly onto the video frames, so they always show and can't be turned off — perfect for social platforms that ignore separate subtitle tracks. Soft subtitles are a separate track the viewer can toggle. This tool burns them in, so the captions travel with the picture everywhere.
Is my video uploaded to a server?
No. Decoding, drawing each caption and re-encoding all happen inside your browser using WebCodecs and mediabunny — the video file and the subtitle file never leave your device.
What subtitle formats can I load?
SubRip (.srt) and WebVTT (.vtt). The tool reads the timings and text from your file and shows how many captions it found before you burn them in. Files ending in .vtt are parsed as WebVTT; everything else is treated as SubRip.
Can I control where the captions appear and how big they are?
Yes. You can place the caption block at the bottom or the top of the frame, choose small, medium or large text, and toggle a dark band behind the text for legibility over busy footage.
Does the audio stay?
Yes. Only the picture is re-encoded to paint on the captions; the original audio track is copied through untouched.
What formats does it accept, and what do I get back?
Drop an MP4, MOV, WebM or MKV file. The output is an H.264 video inside an MP4 container with the captions hardcoded into every frame — the most widely compatible combination.