SyncMySubsMerge subtitles
Combine two subtitle files into one. Stack two languages together for dual-language subtitles, or join two files in sequence. It all runs in your browser, with nothing uploaded.
Add a file to each slot to merge them.
Two ways to combine subtitles
The most common merge is dual-language: two translations of the same video shown together, one line above the other. Because both tracks are timed against the same video, their cues overlap, so this tool combines any cues that share a time window into a single displayed cue rather than stacking two separate subtitles on top of each other. Timing is preserved to the millisecond.
The other case is sequential, where two files cover different parts of one video and you want a single file. Choose sequential to merge and sort both by time, and tick the offset option if the second part restarts its clock at zero. Everything happens in your browser, so nothing is uploaded.
FAQ
How do I make a dual-language subtitle file?
Drop your two language files into the two slots and choose Dual-language (stack). Cues that share a time window are combined into a single cue, with the first file's line on top and the second below, so both languages show together.
What if the two files overlap in time?
For the dual-language mode, overlapping cues are merged into one displayed cue for the exact window they share, so you never get two separate subtitles fighting for the same moment. Timing is kept to the millisecond.
Can I join two parts of the same video?
Yes. Choose Sequential (join) to combine both files into one, sorted by time. If the second file starts its own clock at zero, tick "start the second file after the first" so it is placed after the first part instead of overlapping it.