Subtitle Shifter
Shift SRT or VTT subtitles earlier or later by an exact number of milliseconds. Preview the timing and download in the original format.
Positive values delay subtitles. Negative values show them earlier.
Buttons adjust by 100 ms. Enter whole milliseconds.
Subtitle Preview
The converted preview is not available yet.
Choose a subtitle file to start previewing.
Choose a subtitle file to start previewing.
No subtitle result yet
The result appears automatically when your file and encoding are ready.
How to shift subtitle timing
- Choose your subtitle. Select or drop one SRT or VTT file. If asked, check the decoded text and confirm its encoding.
- Set the time offset. Enter whole milliseconds: positive values delay subtitles, negative values show them earlier. The result updates automatically, starting at 0 ms.
- Download or preview. Save the result using the download above the preview. Output stays in the input format. You can also compare Original and Converted, and review any repairs, skipped entries or format changes.
Format notes
Output stays SRT or VTT, encoded as UTF-8 without a BOM. Text and formatting are retained; valid VTT cue settings, styles, regions and notes are preserved. Inline timestamps shift with the cues. External HLS timestamp mapping is removed when timing changes. Preview shows text and basic formatting; it does not reproduce every VTT style or position.
Frequently asked questions
How do I make subtitles appear earlier or later?
Enter a negative offset to show subtitles earlier, or a positive offset to delay them. For example, −500 moves every subtitle 500 milliseconds earlier. Each adjustment starts from the original file.
What happens to subtitles before zero?
An entry ending at or before zero is removed. If only its start crosses zero, the start is clipped to zero and its shifted end stays unchanged. The processing changes show which entries were affected. The original file remains available for preview.
Can I shift ASS or SSA subtitles?
This tool accepts SRT and VTT. Convert ASS or SSA to SRT first using ASS to SRT, then shift the resulting text subtitles.
Does the tool change my subtitle format?
No. SRT stays SRT and VTT stays VTT. The result updates automatically after a valid offset is entered. There is no Apply button.
Is my subtitle uploaded?
Your subtitle file is read and processed in your browser. Its content and filename are not uploaded to a server. The page still requests the resources needed to run the website.