Subtitle Overlap Fixer

Runs in your browser — nothing is uploaded

.srt · .vtt · .txt

Subtitle file

Drop an .srt, .vtt or .txt fileor click to choose a file

Or paste subtitles

Options

Minimum cue duration100–1000 ms · default 300

Sort cues by start time first

Overlaps found: —
Cues adjusted: —
Minimum-duration extensions: —

Adjusted cues

Old time → new time. Text is unchanged.

Adjusted cues are listed here after you fix a file.

Fixed file

No fixed file yet

The fixed file will appear here.

How to fix overlapping subtitles

Add the subtitle file

Drop an .srt, .vtt or .txt caption file on the page, or paste the subtitles into the text area. Load sample shows a short track with overlaps already in it.
Check the options

Minimum cue duration is the shortest a moved cue may last, 300 ms by default. Leave Sort cues by start time first switched on unless the order in the file is deliberate.
Fix the overlaps

Press Fix overlaps. The summary shows how many overlaps were found, how many cues changed and how many were extended to the minimum duration.
Review the changes

The list shows the first adjusted cues with the old and new start, and the old and new end when a cue was extended. Copy summary puts that list on the clipboard.
Download the fixed file

Download saves the result as the original name plus -overlap-fixed, in the same format it came in. A file with no overlaps still downloads; an SRT file comes back renumbered from 1.

Common uses

After merging two subtitle files

Two tracks that were each fine on their own often collide where they meet, or interleave. Sorting by start and pushing each overlap removes the collisions in one pass.

After shifting part of a track

Delaying or advancing one section of a file can push its first cues into the end of the section before. The fixer repairs those joins without touching the rest.

Before uploading captions to a platform

Some video platforms and players reject or mis-render captions with overlapping cues. Running the file through first gives a clean, renumbered track.

Cleaning up auto-generated captions

Machine-timed captions often end each cue slightly after the next one begins. The fix is small per cue, and the summary shows how many were affected.

Why do subtitle cues overlap?

Overlapping cues are almost always a side effect of another edit. Merging two subtitle files, shifting one part of a track, converting between frame rates or rounding timestamps can leave a cue starting a few hundred milliseconds before the previous one has ended. Players handle that badly: some show two lines stacked on top of each other, some flash one line for a frame, and some drop a line altogether. Fixing it by hand means reading every timing line. This tool finds each cue that starts before the previous one ends, moves its start to exactly that end, and makes sure the moved cue stays on screen for a minimum duration.

Subtitle Overlap Fixer repairs SubRip (.srt) and WebVTT (.vtt) caption files in which a cue starts before the previous one has ended. It sorts the cues by start time, then walks through them in order: when a cue starts too early, its start is moved to the moment the previous cue ends. If that leaves the cue shorter than the minimum duration — 300 ms by default, adjustable from 100 to 1000 ms — its end is extended to reach it. It is written back in the format it came in: SRT cues are renumbered from 1, and WebVTT cues keep their identifiers.

Only timings change. Cue text, line breaks and WebVTT cue settings are copied through exactly as read, and no cue is ever removed for overlapping. WebVTT NOTE, STYLE and REGION blocks are not carried into the output. The summary tells you how many overlaps were found, how many cues moved and how many were extended, and the list shows the first fifty changes with their old and new times so you can check them against the video before you download. The file is read and fixed in your browser; it is not uploaded.

Overlaps usually come from another edit, so this tool pairs with the others that make them. Join parts with the Subtitle Merger, move a track with the Subtitle Shifter, correct drift with the Subtitle FPS Converter, strip hearing-impaired tags and formatting with the Subtitle Cleaner, and change format with SRT to VTT.

How it compares

Desktop subtitle editors can fix overlaps too, usually with more strategies to choose from — trimming the earlier cue's end instead of moving the later cue's start, for example, or splitting the difference between them. They are the better choice when you edit subtitles often and want fine control over each decision.

This page does one thing: it moves overlapping starts to the previous end and applies a minimum duration. One predictable rule means the result is easy to check, and the list of changes shows exactly what happened. It needs no install, and the file stays in the browser tab.

It is a timing tool, not an editor. It does not correct translations, spelling or line length, does not detect the frame rate or offset of a track, and does not look at the video. If a cue's text is wrong, fix it in an editor; if its timing collides with the next one, this is the quicker route.

Tips

If every cue is out by the same amount, the problem is an offset rather than an overlap. Use the Subtitle Shifter for that, then run this tool if the shift created collisions.
If the subtitles drift further out as the video plays, fix the frame rate first with the Subtitle FPS Converter, then fix any overlaps that remain.
Leave sorting on for merged files. Switch it off only when cues are out of order on purpose; with sorting off, an out-of-order cue is pushed after the one before it instead.
A warning appears when a chain of overlaps moved some cue by more than five seconds. That usually means two tracks were merged without being aligned — check the result against the video.
Raising the minimum duration keeps very short interjections readable, but every extension pushes the next overlap slightly further, so keep it modest.

Frequently asked questions

How does the Subtitle Overlap Fixer fix overlapping cues?

It sorts cues by start time, then moves the start of every cue that begins before the previous one ends to exactly that end. If the moved cue would then last less than the minimum duration (300 ms by default), its end is extended to reach it. The result keeps its format, and SRT cues are renumbered from 1.

Does it change my subtitle text?

No. Only start and end times change. Cue text, line breaks and WebVTT cue settings are copied exactly as read. WebVTT NOTE, STYLE and REGION blocks are left out of the output.

Can it delete cues?

No. Every cue in the input is in the output. An overlapping cue is moved later, never dropped, even when the overlap is large.

What is the minimum cue duration for?

When a cue's start moves later, it can end up lasting only a few milliseconds, or none at all. The minimum duration extends such a cue so it stays on screen long enough to read. It applies only to cues that were moved, and you can set it between 100 and 1000 ms.

Should I leave Sort cues by start time first on?

In almost every case, yes, especially after merging files. With sorting off, cues are processed in the order they appear, so a cue that is out of order is pushed to after the one before it rather than moved back into place.

What if the file has no overlaps?

The summary shows zero and you can still download the file. An SRT file comes back renumbered from 1, which is useful after merges that left gaps or duplicates in the numbering. A WebVTT file keeps its cue identifiers.

Why does it warn that a cue moved by several seconds?

Each moved cue can push the next one, so a long run of overlapping cues can move a later cue a long way. When the largest move is over five seconds the page says so, because that usually means two tracks were combined without being aligned. The file is still produced; check it against the video.

Is my subtitle file uploaded?

No. The page reads the file and fixes it in your browser. The FindUtils API and MCP server offer the same fix as subtitle_overlap_fix; if you call them, the caption text is sent to FindUtils over TLS for processing and is not stored or logged.

Which formats does it accept?

SubRip (.srt) and WebVTT (.vtt). A .txt file is accepted when it contains SRT or WebVTT cues. The output uses the same format as the input: WebVTT in gives .vtt out, anything else gives .srt.

Will it fix subtitles that are out of sync with the audio?

Not on its own. Overlaps are cues colliding with each other; being out of sync with the audio is an offset or a frame-rate problem. Use the Subtitle Shifter for a constant offset or the Subtitle FPS Converter for drift, then run this tool if those leave overlaps behind.

Run it from code

$ curl -X POST \
  api.findutils.com/api/tools/subtitle-overlap-fix/execute \
  -d '{"input":"1\n00:00:01,000 --> 00:00:04,000\nFirst line.\n\n2\n00:00:03,000 --> 00:00:06,000\nSecond line starts too early.\n"}'

$ claude mcp add findutils \
  --transport http https://mcp.findutils.com/
# then call findutils:subtitle_overlap_fix

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