How do I sync subtitles with a video?

Play the video and note the time when one line is spoken. Drop the subtitle file here, choose Shift all lines, then From one line, and type that line's number and the time. Every line moves by the same amount. If lines near the end are still off, use two-point sync with a second line near the end.

Why are my subtitles right at the start but late by the end?

They were timed for a version of the video that runs at a different speed, most often a 23.976 or 24 fps release played against a 25 fps one, about 4% apart. A plain shift cannot fix that. Two-point sync or the matching frame-rate preset stretches the times so both ends line up.

Can I use this as an SRT editor?

For timing and quick text fixes, yes: you can move every line, stretch the timing and correct the words of any line, and the file keeps its numbering and formatting. It does not add, delete, split or retime single lines; for that, use a desktop subtitle editor.

How do I tell which frame rate the subtitles were made for?

Watch how the gap grows. A gap that grows by about 2.4 to 2.5 seconds a minute means 23.976 or 24 against 25. A gap of about 7 seconds over a two-hour film means 23.976 against 24. If you are not sure, two-point sync works it out from two lines, and the page shows the speed change it found.

Is my subtitle file uploaded?

No. The file is read and fixed in your browser and is not uploaded. The page records ordinary analytics events, such as the fix you used and the file format, never the file, its name or its text. The fixed file is saved as UTF-8.

Subtitle Sync Tool

Subtitles out of step with the video? Drop the SRT or VTT file, shift every line, match two lines to the video to fix drift, or convert between 23.976, 24 and 25 frames per second. Check each line before and after, correct a typo, and download the file in the same format. Free, no account, and the file is not uploaded.

Drop an .srt or .vtt file here or click to browse

One SRT or WebVTT file up to 5 MB.

Your file is read in your browser and is not uploaded.

How to sync subtitles

Play the video next to this page so you can read off the right times.

1
Add the subtitle file
Drop the .srt or .vtt file on the box, pick it, or paste its text. The page shows how many lines it has and when the first and last one appear.
2
Pick the fix and enter the times
Note when a line is spoken in the video. Shift all lines by seconds, or type the line number and the time it should start; for drift, do that for one line near the start and one near the end.
3
Check and download
The table shows every line's start before and after. Fix a typo with Edit, watch for the warnings, then download the file with -synced added to its name and test it in your player.

Which fix do you need?

Watch the first and the last few minutes of the video with the subtitles on. What you see tells you which fix to use.

Off by the same amount all the way
Every line is, say, 2 seconds late at the start and 2 seconds late at the end. Use Shift all lines: enter -2, or tell the page when one line should start and it works out the shift.
Fine at first, then further and further off
That is drift: the subtitles run at a different speed from the video. Use two-point sync: give the right start time for a line near the beginning and one near the end, and every line in between is stretched to fit.
About 2.5 seconds off for every minute
A gap that grows by roughly 2.4 to 2.5 seconds a minute is the 4% gap between a 23.976 or 24 fps release and a 25 fps one. Pick the matching frame-rate preset, or use two-point sync if you are not sure which way round it goes.
A typo or a wrong word
Press Edit next to any line in the table to change its text. Italics and other tags stay as you type them. Adding, deleting or splitting lines needs a full subtitle editor.

Why subtitles drift out of sync

A subtitle file is only a list of times and words. It matches one particular version of a film or episode, and any other version can be off. The three usual reasons are a different frame rate, a different cut, and a different start.

Frame rate: cinema film runs at 24 frames per second. For the 25 fps PAL standard used in much of Europe, film is simply played about 4% faster, so a release is shorter and every scene arrives a little earlier. For NTSC, film is slowed by 1000/1001 to about 23.976 fps and then spread over 29.97 video frames with 2:3 pulldown, which keeps the 23.976 running time. Subtitles timed for one of these versions drift steadily against another.

Cut: a director's cut, a TV edit or a release with a scene removed matches the file up to that scene and is off by a fixed amount after it. Start: an added studio logo, a recap or a shorter intro moves everything by the same few seconds. This page applies one fix to the whole file, so a jump in the middle needs a desktop subtitle editor that can shift a range of lines.

Shifting and stretching only move the times. The page never reorders lines; a line that would start before 0:00 is set to start at 0:00 and counted, and a line left ending at 0:00 is flagged, because WebVTT requires every cue to end after it starts. Lines that overlap are listed too: WebVTT allows overlapping cues, and two people talking at once can be on purpose, but a fix that creates many is a sign the times are wrong.

Need the other format as well? The SRT to VTT Converter turns SRT into WebVTT and back, and fixes encoding and line endings.Only have a transcript without times? The TXT to SRT Converter makes a timed SRT from plain text.

Frame-rate conversions at a glance

Each preset multiplies every time in the file by the same factor. The last column is where a line at 1:00:00 ends up.

Subtitles made for (fps)	Your video (fps)	Times multiplied by	1:00:00 becomes
23.976 / 29.97	25	0.95904	57:32
25	23.976 / 29.97	1.04271	1:02:33
24	25	0.96000	57:36
25	24	1.04167	1:02:30
24	23.976 / 29.97	1.00100	1:00:03
23.976 / 29.97	24	0.99900	59:56

NTSC releases of films play the 23.976 fps film with 2:3 pulldown at 29.97 video frames a second, so their running time matches 23.976, and both share a preset. Video shot at 29.97 for TV keeps its running time when it is converted to 25 and usually needs no stretch at all.

Sources

Every subtitle starts as a transcript

Before anyone times a subtitle, someone writes down what was said. ParrotNotes does that part for your meetings, calls and lectures: it records on your phone and gives you the transcript and a summary, free for 100 minutes of recording a month.

Get Started Free

Subtitle Sync Tool

How to sync subtitles

Add the subtitle file

Pick the fix and enter the times

Check and download

Which fix do you need?

Off by the same amount all the way

Fine at first, then further and further off

About 2.5 seconds off for every minute

A typo or a wrong word

Why subtitles drift out of sync

Frame-rate conversions at a glance

Every subtitle starts as a transcript

Related tools

Subtitle Sync FAQ