Files stay in the browser while timestamps are shifted and rebuilt.
Load common subtitle sources and normalize the result as clean SRT.
Move every cue forward or backward in milliseconds or seconds.
Download or copy the synced file as soon as the preview is ready.
Step 1
No file loaded
Load your subtitle source
Supported inputs: .srt, .vtt, .ass. Files are processed locally and never leave this page.
Drag and drop upload
Paste raw subtitle text
Private on-device timing edits
Drop SRT, VTT, or ASS files here
Click to browse or drag one subtitle file into the workspace.
Detected source
Waiting for subtitles
Tip: Paste raw subtitle text or drop a file. Timing stays private and local.
Step 2
Output not ready
Build the shifted export
Shift blueprint
Delay 0 milliseconds
Output is rebuilt as a clean SRT file for broad player and editor compatibility.
Direction
Delay
Clamp
Off
Export
SRT
Examples: 500 = half a second, 1000 = one second.
Common amounts
Simple rule
Make subtitles later = the text appears later. Make subtitles earlier = the text appears sooner.
Current status
Ready to shift. Add a file or paste subtitles to begin.
Shifted subtitle output
Synced SRT preview
How to shift subtitle timestamps without breaking sync
Adjust cues forward or backward while keeping dialogue text intact. Export a clean SRT in seconds.
Subtitle Shifter is a browser-based timing tool that moves your subtitles ahead or behind by any offset you choose. Upload or paste SRT, VTT, or ASS captions, set the shift amount in milliseconds or seconds, and choose whether to delay (+) or advance (-). The tool recalculates every timestamp, keeps the original text untouched, and outputs a synced SRT file you can drop into players, editors, or translation workflows.
Use clamping when you advance subtitles to prevent negative times; cues that would dip below zero are pinned to 00:00:00,000 so your file stays valid. VTT inputs are normalized to SRT output, while ASS dialogue lines are parsed and converted to SRT with the original line text preserved. Everything runs client-side, so you can correct timing issues offline, inside a secure environment, or on slow connections.
After shifting, you can copy the output to your clipboard or download the updated file with a single click. If you need to rerun the process, reset clears the fields instantly. Pair this tool with format conversion or cleaning to polish your captions before publishing.
Subtitle shifter FAQ
Will shifting affect subtitle text or numbering?
No. Only timestamps change. Text lines are preserved and SRT numbering is regenerated sequentially.
Can I advance subtitles without creating negative times?
Yes. Enable "Clamp negative timestamps" to pin any value below zero to 00:00:00,000.
What formats are accepted?
SRT, VTT, and ASS inputs are accepted. Output is provided as SRT for broad compatibility.
Is my file uploaded to a server?
No. Processing happens locally in your browser; nothing is stored or sent.
Do VTT and ASS cues keep their timing?
Yes. VTT times and ASS dialogue start/end fields are shifted and converted to standard SRT timestamps.