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Subtitle Timing Shifter

Fix out-of-sync SRT and VTT subtitles by shifting all timestamps

What is the Subtitle Timing Shifter?

The subtitle timing shifter works like this: it shifts every timestamp in an SRT or VTT subtitle file by a constant offset - negative to pull captions earlier, positive to push them later - preserving numbering and text. Everything happens on your device - the input never leaves your tab unless the tool clearly states it performs a server-side lookup.

How to use the Subtitle Timing Shifter

1. Paste the subtitle file content (or open the .srt in a text editor and copy it).
2. Enter the offset: play the video, find when a line is spoken, and enter spoken-time minus displayed-time.
3. Watch the live output to sanity-check the first few cues.
4. Download the corrected .srt or .vtt.

Features

• Powered by in-browser FFmpeg (WebAssembly)
• Your files never upload anywhere
• Progress shown while processing runs

Common mistakes to avoid

• Choosing bitrates below the platform minimum
• Re-encoding already-compressed files repeatedly

Examples

Input	Result
Subtitles 4.6s late	Shift -4.6 → every line lands on the speech

Best used for

• Getting a reliable answer for subtitle timing shifter without installing an app
• One-off tasks done in under a minute from any device
• Checking results before committing them to something important
• Working on a phone where desktop software is unavailable

Privacy

Audio and video processing runs on your device with WebAssembly FFmpeg; your files are never uploaded.

Frequently asked questions

How do I find the right offset fast?

Note the time a caption appears, then find the actual speech moment in the video - the difference is your number. One iteration usually nails it.

Does it fix stretched or drifting subtitles?

No - a constant shift fixes synced-but-offset files; drift (growing error over time) needs per-line re-timing in a dedicated subtitle editor.

Which subtitle formats does it shift?

SRT and VTT - every timestamp moves by your constant offset, negative to pull captions earlier, with line content preserved exactly.

Why would subtitles need a constant shift?

The classic late-subtitles fix: a rip whose captions run consistently ahead or behind the dialogue. One offset applied to every line corrects the whole file.

Related tools

• YouTube Transcript Extractor - Get any video transcript as text, timestamps or an SRT file
• Video to Audio - Extract MP3, WAV, M4A audio from MP4, MKV, MOV video files
• Audio Trimmer - Trim MP3, WAV, M4A audio files online by timestamp
• Quick Notes - Notes with autosave in your browser

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Zoven offers 200+ free browser tools. Browse by category - Calculators, Converters, Generators, Developer Tools and Media Tools - or read workflow guides on the Zoven blog.