Subtitle file merger
Join two SRT files into one. Append when a video was split into parts and each part has its own subtitles, or combine languages when you have two translations of the same video and want both on screen. Everything runs in your browser, the files are never uploaded, and the result is renumbered from 1.
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Seconds added to every cue of file two. Use the button for the end of file one.
Three steps
Paste or open the first SRT file, then the second.
Choose Append (with an offset for part two) or Combine languages.
Check the merged, renumbered cues and download merged.srt.
Useful for
What it checks
Two kinds of merge
"Merge SRT files" can mean two different jobs. Pick the one that matches your video.
Use Append when the video is one long piece but its subtitles came as two files, for example a film split across two discs or a talk recorded in two sessions. Part two's file is usually timed from zero, so enter an offset: the length of part one's video in seconds. If part one runs 12:30, the offset is 750, and a cue at 00:00:00,500 in part two lands at 00:12:30,500. All cues are then numbered from 1.
Use Combine languages when both files belong to the same video, for example English and Hindi. The cues of both files are put in time order. Where a cue in file two has the same start and end as a cue in file one, give or take 50 milliseconds, the two become one cue with file one's line on top and file two's line underneath. Cues with different timing stay separate.
Combining works best when the translation was made from the same SRT, so the timings match cue for cue. If the timings differ, overlapping cues stay separate, and players handle overlaps differently: many stack them, some show only one. Test the result in your player. Two languages double the text on screen, so keep each line short and check reading speed before you publish.
Searches for "merge SRT with MP4" usually mean putting subtitles into the video file, either burned into the picture or added as a selectable track. This tool only joins subtitle files. For the video step, use HandBrake, VLC or FFmpeg; our guide to burning subtitles covers all three. CapsAI's own captioning makes captions from your video's speech and burns them into the MP4; it does not import SRT files.
Questions
Paste or open both files, choose Append or Combine languages, and download merged.srt. Append places file two after file one using the offset you enter; Combine languages interleaves both files by time.
The running time of part one's video in seconds, if part two's subtitles start from zero. The "Use the end of file one" button fills in when part one's last caption ends, which is a good starting point when the video has no long silence after it. A 45-minute part one needs an offset of 2700. If part two's subtitles were already timed against the full video, use 0.
Yes. Combine languages joins cues that share the same timing into one two-line cue, file one on top. It works best when both files were timed from the same source.
No. Burning subtitles into a video, or adding them as a track, is done in a video tool such as HandBrake, VLC or FFmpeg. See our guide to burning subtitles with those three.
No. Both files are read and merged in your browser. The tool is free and needs no account.
Merge two, download the result, then paste it back as file one and add the third file as file two.
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