How to sync subtitles
- Open your subtitle file (
.srt,.vtt,.ass,.sbvor.sub) or paste it. - Optional but easiest: click Check on your video and load the video. It plays in your browser with the corrected subtitles on top; nothing is uploaded.
- Pick a method: Shift if every line is off by the same amount, Match one line to set the delay from a line you can hear, or Match two lines if the gap grows during the film.
- Watch a few lines on the player, adjust, then click Download SRT.
Which method do I need?
| What you see | Use |
|---|---|
| Every subtitle is early or late by the same amount | Shift by that many seconds. Subtitles too early → positive number (adds a delay); too late → negative. |
| You can hear exactly when one line is said | Match one line: pause the video on that moment and click Use video time. The whole file moves by the difference. |
| Fine at the start, more and more off later | Match two lines: one near the start, one near the end. The timing is stretched between them, which also fixes a wrong frame rate. |
| Fine until a certain point (an ad break, a cut scene) | Shift with from … on set to that time: earlier subtitles stay where they are. |
| Subtitles for a 25 fps (PAL) release on a 23.976 fps video | Frame rate conversion — the most common cause of slow drift. |
Subtitle delay in a player vs. fixing the file
Players such as VLC can delay subtitles on the fly (in VLC the G and H keys), but the delay is forgotten when you close the video and doesn't help on a TV, phone or upload. Syncing the file here fixes it everywhere, and you can use the delay you found in the player as the shift.
Frequently asked questions
Can it sync subtitles to the audio automatically?
No. The tool doesn't listen to the soundtrack. You tell it the offset — or the moments one or two lines are spoken — and it recalculates every time exactly.
My subtitles show up too early. Positive or negative?
Positive. A shift of +2 makes every subtitle appear 2 seconds later. If they appear too late, use a negative number such as -1.5.
The delay gets bigger during the movie. Why?
The subtitles were made for a release with a different frame rate or cut. Use Match two lines with one line near the start and one near the end, or the Frame rate list if you know both rates (25 vs 23.976 is the classic case).
Does syncing change the text or the format?
The text stays as it is. You can save as SRT, VTT, SBV, ASS or plain text. Styling and positions of an ASS input are not kept, even when you save as ASS.
Are my files uploaded?
No. Text, subtitle files and videos are processed by your browser on your own computer. Nothing is sent to a server.
Accented or Cyrillic letters look garbled. How do I fix it?
The file uses an old encoding. Pick the right one in the Encoding menu under the input (for example Windows-1251 for Russian, Windows-1250 for Central European, Windows-1252 for Western languages). The output is always saved as UTF-8.