Shift Subtitles

What this tool does

This tool moves subtitle times earlier or later by a fixed amount, in milliseconds, seconds or HH:MM:SS,mmm. You can shift the whole file, the lines from a given subtitle number, or a time range, and check the result on your own video. It fixes a constant delay, not subtitles that drift.

How to shift subtitles

Select Choose files and add subtitle files, or use Paste text.
Set Time shift. Enter 1500 for milliseconds, 1.5s for seconds, or 00:00:01,500. Add a minus sign to move subtitles earlier.
Choose Apply to and select Shift. Check the first five changed lines and any warnings.
Select Download for one file or Download all (ZIP) for several files.

To check against a video, open Preview on your video (optional) and choose Video file. Select a subtitle to seek to it. Move the video to the matching speech and select Set this subtitle to the current video time. Run the tool to apply the new shift and refresh the captions.

Options explained

Time shift defaults to 0. The quick buttons add or subtract 100 milliseconds or one second from the current value.
Apply to defaults to all subtitles. Subtitle numbers start at 1. Time ranges select lines by their original start times, including the end of the range.
Subtitles before zero defaults to trimming lines that cross zero and removing those fully before zero. The other choice removes a line if any part is before zero.
Add UTF-8 BOM is off by default. Use it for older programs that need it.

Example

With Time shift set to +1s, one second is added to both ends of each subtitle:

1
00:00:01,000 --> 00:00:02,000
The kettle is ready.

Output:

1
00:00:02,000 --> 00:00:03,000
The kettle is ready.

Format notes and limits

Reads SRT, VTT, ASS, SSA, SBV and timestamped TXT; saves the same format as UTF-8. Plain text without times needs TXT to SRT first.
Up to 50 files, 20 MB per file and 200 MB in total. Times must stay within 1000 hours.
A selected range can create overlaps at its boundaries. Check the result before replacing your original.
Video captions follow the playhead. If more than 500 subtitles fall in the preview window, the video shows the first 500 and displays a notice. Downloads keep every line.
Need another file format? Use the subtitle converter or SRT to VTT.
For gradual drift, use Sync subtitles with two matching points, or Change subtitle frame rate for a known speed change.

Questions

Should I use a positive or negative delay?

Use a positive value to show subtitles later. Use a negative value to show them earlier. If the words appear before the matching speech, add a positive delay.

Can I shift only part of an SRT file?

Yes. Choose From subtitle number, From start time, or Start times in a range. Ranges use the original start times and include both endpoints.

What happens to subtitles before the start of the video?

By default, a subtitle crossing zero starts at zero. A subtitle ending at or before zero is removed. You can instead remove every subtitle that starts before zero. The result reports how many lines were trimmed or removed.

Will shifting fix a delay that grows during the video?

A fixed shift fits a constant delay. A growing delay needs Sync subtitles to fit two matching points, or Change subtitle frame rate if you know the two speeds.

Does this change the subtitle style?

The output keeps the input format, text and available styling. It is saved as UTF-8. ASS and SSA store times in hundredths of a second, so their output rounds to 10 milliseconds.

Are my files uploaded?

Your files are processed in your browser and are not uploaded to our servers.

Drop subtitle files here

Options