Merge subtitle files into one
Join subtitles for a movie split across two files. Each part keeps its own start offset, so CD2 lands where it belongs. Nothing is uploaded.
Films ripped in the DVD era were routinely split in half, and the subtitles came split too: CD1 runs from zero to about an hour, and then CD2 starts again from zero. Concatenating the two files with a text editor produces something no player can use, because the second half claims to begin at 00:00:00 while the video has already been running for an hour. The fix is an offset — every cue in the second part has to move forward by the length of the first video file. Subtitle Doctor lets you drop the parts in order, suggests each offset from where the previous part’s subtitles ended, and lets you correct it, because only the video knows its true runtime. Load the joined video underneath and you can watch the seam to confirm the second half lands on the right line.
Worth knowing
- The suggested offset is where the previous part’s last subtitle ends, which is not the same as where the previous video ends — trailing silence, credits or a black gap can add seconds. Treat it as a starting point and verify against the video.
- Getting the offset wrong is obvious rather than subtle: the entire second half drifts by a constant amount, so once you correct one line at the seam, every line after it is correct too.
- Parts are merged in the order shown, not the order they were dropped — use the arrows to reorder, which matters when a file manager hands over CD2 before CD1.
- Offsets accept anything readable: "3600", "60:00", or "1:00:00.000" all mean the same hour, so you can paste a runtime straight from your player.
- A part can be pulled backwards with a negative offset, and times are clamped at zero rather than going negative and producing a file no parser will accept.
FAQ
What offset should I use for CD2?
The exact running time of the first video file, which your player shows as the total duration of CD1. The suggestion Subtitle Doctor fills in is the end of CD1’s last subtitle — usually a few seconds short, because films rarely end on a line of dialogue. Load the joined video in the preview and nudge the number until the first line of the second half lands correctly.
Can I merge more than two parts?
Yes. Drop as many parts as you have, put them in order with the arrows, and give each one its start offset. Each part is measured from the beginning of the joined video, not from the part before it, so part three uses the combined length of parts one and two.
Why not just copy and paste the two files together?
Because the numbering and the timing both break. SRT cue numbers would restart at 1 halfway through, and every timestamp in the second half would be an hour too early. Merging rewrites both, so the output is a single valid file with continuous timing.