How to Merge Two SRT Subtitle Files: A Step-by-Step Guide
Learn how to merge two SRT subtitle files: compare them by timecode, pick the best line from each, and test the result in your player.
SRT Merger
Compare two subtitle files side by side, choose the best line in each row and save one merged .srt. Your files are processed in this browser tab and never uploaded.
File 1
or drop it here
File 2
or drop it here
Choose two .srt files to begin. Files must be saved as UTF-8.
| File 1 | Keep | File 2 | |
|---|---|---|---|
Tip: Shift+click a box to keep both versions. Use the Edit button, or double-click a cell, to change text or timecodes.
How to use the SRT Merger
- Prepare your files. Both subtitles must be in sync with the same video and saved as UTF-8. If they are not, read the subtitle sync guide and the text encoding guide first.
- Load File 1 and File 2. Put the translation you trust more in File 1. Use the buttons or drag files onto the boxes. Not sure yet? Press Try with sample files.
- Read the summary. The coloured counts show how many rows are identical, differ, or exist only in one file. Identical rows are greyed out and need no decision.
- Choose lines. By default every row from File 1 is selected. Tick the File 2 box where it is better. Use the bulk buttons if one file is better overall.
- Fix details. Press Edit in a cell to correct a typo or timecode. Press Escape to cancel.
- Save. Press Save merged SRT. The file is sorted by start time, renumbered from 1, and written as
merged.srt. - Test it. Play the file with your video and check a few places, especially where lines from the two files meet.
Controls and shortcuts
| Action | What it does |
|---|---|
| Click a checkbox | Selects that version and clears the other side of the row. |
| Shift + click | Selects a version without clearing the other, so both are kept. |
| Edit button or double-click | Opens the row's lines as editable text with indexes and timecodes. |
| Escape while editing | Discards the edit. |
| Prefer File 1 / Prefer File 2 | Selects that file in every row where both exist. |
| Keep both | Selects both versions in every row that has two different versions. |
What the colours mean
The summary chips and table use the same colours: yellow for identical rows, red for rows that exist in both files but differ, blue for lines only in File 1, and green for lines only in File 2.
How it works
The tool parses each file into subtitles with a start time, end time and text. It then walks through both lists in time order and groups subtitles that overlap into rows. Because grouping is based on time, it copes with files that split or join sentences differently. When you save, it collects the selected subtitles from every row, sorts them by start time, renumbers them from 1 and writes them with a blank line between entries. Formatting tags such as <i> are kept exactly as written.
Your privacy
All of this happens inside your browser. The files you choose are read with the browser's own file APIs, compared in memory and saved back to your device. They are not uploaded, stored or logged by this site. To remember the last folder you used, supported browsers keep a reference to your most recently opened file in local browser storage on your device. It is never sent to us, and you can clear it by clearing site data. See the full privacy details.
Limitations to know about
- It supports .srt files only. For other formats see SRT vs VTT vs ASS.
- Files are read as UTF-8. Older files in other encodings may need converting first.
- It assumes both files are already synchronised with the same video.
- Rows are grouped by overlapping time, so very different segmentation can produce large rows.
Frequently asked questions
Are my subtitle files uploaded to a server?
No. The files are read by your browser and compared on your own device. The page never sends their contents anywhere. You can check this by opening your browser's developer tools on the Network tab while you merge, or by going offline after the page has loaded.
Which subtitle formats does the tool support?
It reads and writes SubRip (.srt) files saved as UTF-8. If your subtitles are in another format such as WebVTT or ASS, convert them first. See the subtitle format comparison.
How does the tool decide which lines belong together?
It aligns the two files by timecode, not by line number. Lines that overlap in time are grouped into one row, so two translations that split a sentence differently still line up.
How do I keep both versions of a line?
Hold Shift while you click a checkbox. A normal click selects one side and clears the other; Shift+click leaves the other side as it is. The bulk button “Keep both” does this for every row that has two versions.
Will it change my original files?
No. Your originals are never modified. Edits and selections only affect the merged file, which is saved as a new file.
Why does almost every row show as different?
The two files are probably out of sync or use different text encodings. Fix the timing first with the sync guide, and convert both files to UTF-8 using the encoding guide.
Does it work on a phone or tablet?
Yes. On narrow screens each row becomes a stacked card with large checkboxes, and every cell has an Edit button, so you do not need a double-click.
Is there a limit on file size?
There is no fixed limit. A feature-length subtitle file is only a few hundred kilobytes, which any modern browser handles instantly. Very large files are limited only by your device's memory.
Can I merge more than two files?
Merge two at a time. Save the first result, then load it as File 1 together with the third file as File 2.