Subtitle Merge API
https://api.findutils.com/api/tools/subtitle-merge/execute Join several SubRip (.srt) or WebVTT (.vtt) caption files into one track. Append (the default) lays the files end to end: each later file is offset past the previous one's last cue, plus an optional gap, so parts exported separately — which normally restart at 00:00:00 — become one continuous timeline, and the cues are renumbered from 1. Dual stacks two files on one timeline instead, keeping the primary file's timing and appending each secondary cue's lines to the cue it overlaps, which is how a bilingual subtitle track is built. Inputs may mix the two formats; each is parsed natively and the output is written in one format. A file that cannot be parsed is reported by position and the rest still merge. Cue text is never translated or edited.
Request body
application/json-
inputs
array required
Caption file contents, one string per file, in the order they should appear. At most 20.
-
mode
string optional
append lays the files end to end on one continuous timeline. dual stacks them on the primary file's timing for a bilingual track. Default append. One of
append · dual. Default"append". -
gap_ms
integer optional
Silence inserted between parts in append mode, in milliseconds. Ignored in dual mode. 0 to 60000. Default 0. Default
0. -
format
string optional
Output format. auto keeps the format of the first file that parsed. Default auto. One of
auto · srt · vtt. Default"auto". -
primary
integer optional
Dual mode only: the 0-based index of the file whose timing is kept. Default 0, the first file. Default
0. -
keep_absolute
boolean optional
Append mode only: the files already share one timeline, so keep every timestamp as written and interleave the cues by start time instead of offsetting. Use this when the parts were cut from one long recording without being renumbered. Default false. Default
false.
Example arguments
Verified{
"inputs": [
"1\n00:00:01,000 --> 00:00:04,000\nPart one, first line.\n\n2\n00:00:05,000 --> 00:00:10,000\nPart one, last line.\n",
"1\n00:00:00,500 --> 00:00:03,000\nPart two, first line.\n\n2\n00:00:04,000 --> 00:00:08,000\nPart two, last line.\n"
],
"mode": "append",
"gap_ms": 0
}More Media tools
- Ass To Srt Flatten an Advanced SubStation Alpha (.ass) or SubStation Alpha (.ssa) subtitle script to plain SubRip (.srt).
- Sbv To Srt Convert a YouTube SubViewer (.sbv) caption export to SubRip (.srt), or back again.
- Srt To Vtt Convert SubRip (.srt) captions to WebVTT (.vtt) and back.
- Subtitle Fps Convert Rescale every cue in a SubRip (.srt) or WebVTT (.vtt) caption file from one frame rate to another, so a track that slowly drifts out of sync
- Subtitle Shift Shift every cue in a SubRip (.srt) or WebVTT (.vtt) caption file by one fixed offset, so a track that runs early or late lines up with the a