SyncMySubsExtract subtitles from a video file
Pull the embedded subtitle track out of your own .mkv, .mp4, .webm, or .mov and save it as SRT or VTT. It reads only the subtitle track, never the video, so even large files stay on your device and nothing is uploaded.
How it works
A video container like MKV or MP4 can carry the subtitles as a separate text track alongside the picture and sound. This tool walks the file's structure in your browser, reads just that subtitle track, and rebuilds it as a standard SRT or VTT file. Because it skips over the video and audio instead of decoding them, it never loads the whole file into memory, so a multi-gigabyte movie uses about as little memory as a small clip. Large files simply take longer to scan, and it is slower on phones than on a computer.
Two kinds of subtitles can't be turned into text here. Image-based tracks (PGS, VobSub, or DVB) store each line as a picture, so they would need OCR. Burned-in subtitles are part of the video picture itself and aren't a separate track at all. The tool detects both cases and tells you plainly instead of producing an empty or broken file. Use it on videos you made, licensed, or otherwise have the right to use.
New to this, or not sure your video has a track to extract? How to get subtitles from your video →
FAQ
Which video files does this work with?
MKV, MP4, WebM, and MOV files that contain a text subtitle track: SubRip, ASS/SSA, or WebVTT inside MKV/WebM, and 3GPP timed text or WebVTT inside MP4/MOV. It reads the subtitle track only and never touches the video or audio, so it works on large files without loading the whole video.
Is my video uploaded anywhere?
No. Everything runs in your browser. The video is read directly from your device in small pieces to find the subtitle track, and nothing is ever sent to a server. Use it only on videos you made, licensed, or otherwise have the right to use.
It says my subtitles are image-based. Why can't it extract them?
Some discs and rips store subtitles as pictures rather than text (PGS, VobSub, or DVB). There is no text to pull out of a picture, so turning them into SRT would need OCR, which this tool doesn't do. The tool detects these and tells you rather than producing a broken file.
It found no subtitle track. What does that mean?
The video has no separate subtitle track to extract. If you can see subtitles when the video plays but this finds none, they are most likely burned into the picture, which can only be recovered with OCR. Some files simply ship without subtitles.