OfflineSubs

MP4 to SRT converter

Turn an MP4 video into a timed SRT subtitle file without uploading it anywhere. Your video stays on your machine the whole time.

Drop your MP4 video here
or click to choose · mp4 mov m4v · audio files work too

Converting MP4 to SRT

An MP4 file carries its sound in an audio track alongside the picture. This tool reads that track, recognises the speech in it and writes out an SRT file — a plain text file where every line of dialogue is paired with a start and end time.

Because the whole thing runs as WebAssembly inside your browser, the video is never sent to a server. That matters when the footage is unreleased, confidential, or simply large: a 2 GB MP4 would take far longer to upload than it takes to transcribe locally.

What you get

FAQ

Does it read the audio track of my MP4?

Yes. The video is decoded in your browser and only its audio is used. The picture itself is never uploaded or inspected.

Is there a file size limit?

No artificial limit, but very large files are held in memory. On a desktop, clips up to roughly 10 minutes work comfortably; for longer material, split it into parts.

Will the timings match my video?

Yes, the SRT timings start at zero and follow the video's own timeline. If your edit starts later, use the shift buttons to offset everything at once.

How accurate is it?

Clear speech with little background noise transcribes well. Overlapping speakers, heavy accents or music underneath will reduce accuracy, so plan to proofread the result — the editor is there for exactly that.