Subtitles appearing too early, too late or gradually drifting out of sync? Adjust a UTF-8 SRT with a constant shift, or use two matching dialogue moments to correct timing drift.
Fix SRT subtitle timing
Choose a UTF-8 SRT or paste its text. Processing stays in this browser. Video/audio is not analyzed.
Use two matching dialogue moments, one near the start and one near the end. Times: HH:MM:SS.mmm. Changes apply to the entire file.
Preview: first 10 retained cues
How to fix subtitle timing
- Choose a UTF-8 SRT file or paste its text.
- For a constant delay, choose Shift every cue equally and enter seconds.
- For gradual drift, choose the two-anchor mode and enter the original SRT times and correct video times for two matching moments.
- Click Fix subtitle timing and check the preview and corrected text.
- Download the corrected SRT, load it in your player and check the beginning, middle and end.
Positive or negative shift?
A positive shift displays subtitles later. Use +2.5 when subtitles appear 2.5 seconds before the spoken dialogue. A negative shift displays them earlier. Use −2 when subtitles appear 2 seconds after the dialogue. Constant shifting changes every start/end time equally and keeps cue durations the same.
Fix drift with two dialogue moments
If the gap gets larger as the video plays, a single shift may not be enough. Pick one clearly recognizable dialogue near the start and another near the end. For each, enter its original subtitle start time and the time it should start in the video, using HH:MM:SS.mmm, for example 00:10:12.500. A comma is also accepted before milliseconds.
Example: the first cue starts at 00:00:10.000 but should start at 00:00:12.000. A later cue starts at 00:10:10.000 but should start at 00:10:15.000. The tool maps both moments to those targets and scales the entire timeline between and beyond them. Both start and end times change, so cue durations also scale. Times are rounded to the nearest millisecond.
The later moment must be later in both the SRT and video. The allowed time scale is 0.1 to 10. This is a linear correction; it does not handle missing scenes, separate edits or irregular timing changes. It does not listen to audio or automatically find matching dialogue.
What happens before time zero?
By default, a correction producing negative timestamps stops with a message. The optional clipping setting drops cues that end at or before zero, and clips the start of a cue that crosses zero. The result reports how many cues were dropped or clipped. If every cue would be dropped, no download is created.
Supported SRT and limits
This version accepts plain UTF-8 SRT: a numeric cue index, a start –> end timestamp line and subtitle text, separated by blank lines. Times use two-digit hours from 00 to 99, minutes/seconds 00 to 59 and three millisecond digits. Comma or dot is accepted, and output uses the SRT comma format.
Limit: a 2 MB file, 1 million characters and 10,000 cues. VTT, ASS, SSA and extra positioning settings on the timestamp line are not supported. Each cue must end after it starts. Corrected times must stay within 00:00:00,000 to 99:59:59,999. A correction that rounds a cue to zero duration is rejected.
What changes in the output?
Subtitle text, multiple text lines and inline markup are retained as text. Cue indexes are renumbered from 1, line endings are normalized and timestamps are rewritten. The first 10 retained cues appear in the before/after preview; the download contains the complete corrected SRT. Existing cue order and overlaps are not automatically repaired.
Changing input or settings clears the old result. The selected original file stays unchanged. Processing happens in your browser without uploading the subtitle contents or a video.
If sync still looks wrong
Check the direction of the shift and that both anchor moments refer to the same dialogue in your subtitle and video. Use moments far apart for drift correction. Preview the downloaded file in your player. If the mismatch jumps after an added or removed scene, use a subtitle file matching that video edit or edit the affected section separately.
Frequently asked questions
How do I make subtitles appear later?
Choose constant shift and enter a positive number such as 2 or 2.5 seconds.
How do I make subtitles appear earlier?
Enter a negative shift such as −2 seconds.
Can this fix subtitles that get worse toward the end?
Use the two-anchor drift mode if the mismatch grows steadily. Match one dialogue near the start and another near the end.
Does it sync automatically from the video?
No. You supply the correct timestamps. No video or audio is analyzed.
Can I use Hindi subtitles?
Yes, in a UTF-8 SRT. The text and multiple lines are retained.
Does it support VTT or ASS?
No. This version processes plain SRT only, without extra positioning on timestamp lines.
Will my original file be overwritten or uploaded?
No. The tool downloads a corrected copy and processes the subtitle text in your browser.
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