The subtitle file splitter cuts a single SRT or VTT file into two parts at a timecode you choose. It is most useful when a full-length film subtitle needs to match a two-disc or two-file video release, or when you want to break a long lecture transcript into manageable halves. Each part is renumbered from 1, and Part 2 can be rebased so its timeline starts at zero.
How it works
The tool parses the file into cues with start and end times in milliseconds, detecting SubRip or
WebVTT automatically. Your split timecode — entered as HH:MM:SS, MM:SS or a plain number of
seconds — is converted to a millisecond split point. Each cue is then routed by its start
time: cues starting before the split go to Part 1, and cues starting at or after the split go
to Part 2. Routing by start time keeps every caption intact rather than slicing one cue across
the boundary.
If rebasing is enabled, Part 2 is shifted so its first cue begins at 00:00:00; every other
cue in Part 2 moves by the same offset, preserving the relative timing. Both halves are then
renumbered from 1 and serialised back to the original format.
When to rebase and when not to
Rebase on when the second video file itself starts at zero — as is the case with a two-file or two-disc release where each disc is an independent video file. The player loads Disc 2’s video starting at 00:00:00, so the subtitle must also start at 00:00:00.
Rebase off when the second file is a chapter marker in a single-file rip, or when you are cutting a subtitle for a long lecture clip that carries the original documentary timecode for reference purposes. Keeping the original timecodes means they continue to match the original full-length file.
Common use cases
Two-disc movie releases. A DVD or Blu-ray release splits a long film across two discs at roughly the halfway point. The subtitle file from a rip of both discs needs to be split at the same cut point, with Part 2 rebased to match Disc 2’s timeline.
Long lecture or conference recordings. A six-hour conference recording is often served as two three-hour files. A single subtitle generated for the full recording can be split at three hours to produce two matching files.
Editing out a segment. If you have trimmed a section out of the middle of a video, you may need to split the subtitle at the cut point, remove the middle section, and merge the remaining two parts. This tool handles the split step; a subtitle merger handles the join.
Example and notes
Splitting a film subtitle at 00:55:00 with rebasing on gives a Part 1 that ends around the
55-minute mark and a Part 2 whose first line now reads near 00:00:00 instead of 00:55:xx —
ready to pair with the second video file. Turn rebasing off if your second video still carries
the original full-length timeline.
Note that cues exactly on the boundary go to Part 2, and a cue that starts just before the split but ends after it stays whole in Part 1. All processing happens locally in your browser.