Fix drifting subtitles in an SRT file

Drop an SRT or VTT file

or click to choose one

How to fix drifting subtitles

Add your file
Choose the SRT or VTT file that drifts. Lines near the start fit the video and lines near the end do not.
Pick two subtitles
Play the video and note when one early subtitle and one late subtitle should appear. Type their numbers and their correct start times in the four fields.
Download
Click Fix drifting subtitles, then click Download. Check a line in the middle of the video to confirm the fix.

The subtitles match the first scene but are several seconds late by the end.
You downloaded subtitles for a different release and you do not know its frame rate.
A single shift fixes the start of the film and breaks the end.
Subtitles from a DVD do not fit the streaming version of the same film.
A YouTube caption download slowly gets out of sync on a long video.

Why do my subtitles drift out of sync?

The subtitle file and the video use different speeds or frame rates. The error grows as the video plays, so one shift cannot fix it.

How is this different from a plain shift?

A shift moves every subtitle by the same amount. This tool moves early subtitles by a small amount and late subtitles by a larger one.

Which two subtitles should I pick?

Pick one near the start and one near the end. The further apart they are, the better the fix. Choose lines with clear speech, not music or noise.

What if the subtitles are early at first and late later?

That works too. Enter the correct start of each subtitle, and give the later subtitle the later time.

Should I use the frame rate converter instead?

Use the frame rate converter when you know both frame rates. Use this tool when you do not know them, or when the cause is not a frame rate.

Is my file uploaded?

No. The tool runs in your browser. Your subtitle file never leaves your computer.

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