Free Online Subtitle Timing Shifter
Shift every cue in an SRT, VTT or ASS file by any offset — forward or backward — to re-sync subtitles that lag or rush your video. Millisecond-precise, fully private, runs entirely in your browser.
Features
Fix Every Subtitle Sync Problem
Shift forward when subtitles lag behind, shift backward when they rush ahead of the dialogue. Works with whole-file offsets down to one millisecond.
Forward & Backward Offsets
Add positive delay for subtitles arriving too early, or negative for subtitles lagging behind the audio.
Millisecond Precision
Set the offset in hours, minutes, seconds and milliseconds — no rounding, no drift.
Every Cue, One Click
The shift applies uniformly to every cue in the file — re-sync hundreds of lines in a single operation.
SRT, VTT, ASS — All Supported
Drop any common subtitle file. SubShift auto-detects the format, shifts the timings, and exports the same format back — ready for your player, NLE or web embed.
SRT (SubRip)
The desktop standard used by Premiere, DaVinci Resolve, VLC and most editing software.
VTT (WebVTT)
The web standard for HTML5 video — required by every modern browser-native player.
ASS (Advanced SubStation Alpha)
The styled-subtitle format used by anime fansubs, MKV releases and Aegisub workflows.
100% Private & Free
Your subtitle files never leave your device — SubShift runs as plain JavaScript inside your browser tab. No upload, no account, no watermark.
Zero Server Upload
Files are read, shifted and written back entirely on your own machine.
Instant Download
The shift completes in milliseconds — click and the re-synced subtitle file is ready.
Works Everywhere
Any modern browser — desktop or mobile. Chrome, Firefox, Safari, Edge.
FAQ'S
Frequently Asked Questions
Ask us anything!
Re-Sync Your Subtitles Now
Free, private and instant. No signup, no upload, no watermark — drop a subtitle file, enter the offset, and download the re-synced version in seconds.