Merge Subtitles
Merge two SRT files into bilingual subtitles. Match nearby start times, compare both files and download the merged SRT.
File 1
Primary subtitles. Matched cues use this file’s timing, with its text above File 2.
File 2
For matched cues, this file’s text appears below File 1.
Unmatched cues from either file keep their original timing.
Maximum difference between cue start times. Use 0 to match identical start times only.
0–10,000 ms. Buttons adjust by 50 ms. Changes take effect when you merge.
Subtitle Preview
Choose and confirm each file to preview it. Merge subtitles to make the merged preview available.
Choose a subtitle file to start previewing.
Choose a subtitle file to start previewing.
No SRT result yet
Choose both SRT files and a matching tolerance, then select Merge subtitles to generate the result.
How to merge two SRT files
- Choose both subtitle files. Add two SRT files and check each input encoding. File 1 supplies the timing for matched pairs.
- Set the matching tolerance. Choose how far apart cue start times can be. Select Merge subtitles to apply the value.
- Compare and download. Switch between File 1, File 2 and Merged. Check the matched and unmatched counts, then download the SRT.
How matching works
Each cue in File 1 matches at most one cue in File 2. The closest available start time within the tolerance wins, including the exact tolerance boundary. Ties use File 2’s original order. File 1 is processed by start time and supplies timing for matched pairs, with its text above File 2. Internal line breaks and basic formatting are retained. Unmatched cues from either file keep their original timing. Output is sorted by start time, with File 1 first for equal times, and encoded as UTF-8 without a BOM, with CRLF line endings. Matching does not infer offsets or synchronize different cuts.
Frequently asked questions
What does matching tolerance mean?
It is the maximum difference between two cue start times. A value of 500 ms allows a difference of up to half a second. Use 0 to match identical start times only. Enter a whole number from 0 to 10,000 ms.
What happens to unmatched subtitles?
They are kept in the merged SRT with their original timing. The result shows a separate unmatched count for each file.
Can this automatically synchronize different versions?
It matches nearby start times one to one. It does not detect a global time offset or synchronize different cuts. Adjust the timing first when needed.
Are my subtitle files uploaded?
Your subtitle file is read and processed in your browser. Its content and filename are not uploaded to a server. The page still requests the resources needed to run the website.