Converter Tools
Subtitle Framerate Converter
Convert SRT and VTT subtitles between 23.976, 24, 25, 29.97, 30, 50, 59.94, and 60 fps. Fix subtitle drift caused by NTSC and PAL framerate mismatches.
Subtitle framerate converter
Subtitle input
Paste an SRT or VTT file
Framerate
Convert from one framerate to another
The framerate the subtitle file was timed against.
The framerate your current video file plays at.
Every timestamp is multiplied by 0.959040 (95.904%). A cue at 60.000s will land at 57.542s; a cue at 1800.000s (30 min) will land at 1726.272s.
Extra offset (optional)
Add a constant shift on top of the rescale
Most files only need the framerate change. Use this when the file also has a few seconds of compound delay (for example, an opening credits sequence was trimmed). For a simple offset with no framerate change, the dedicated subtitle delay tool is easier.
Extra offset applied: +0s.
Or: compute the extra offset from a known line
Pick one line in the file. Type its current cue time and the time you want it to appear at in the video. The tool computes the residual offset that the framerate ratio alone does not account for.
Leave both blank to skip this helper.
Range
Which cues should be rescaled?
Output
Rescaled subtitles
Paste an SRT or VTT file above to see the rescaled output here.
When to use framerate rescale
- The subtitles line up at the start of the video, but the gap between the audio and the captions grows the longer it plays. That drift is a framerate mismatch, not a delay.
- The release source ran at one framerate (commonly 23.976 for an NTSC film master) and your local video file is a re-encode at another (often 25 for PAL or 29.97 for NTSC broadcast).
- You changed the playback speed in a player like VLC and want to bake that speed change into a permanent subtitle file.
- For a constant delay (everything is X seconds off, no drift), use the focused subtitle delay tool instead.
Common framerates
- 23.976 NTSC film, most modern streaming downloads, Blu-ray movies (24000/1001).
- 24 cinema masters, DCP, occasional Blu-ray sources.
- 25 PAL broadcast (Europe, Australia, parts of Asia and Africa).
- 29.97 NTSC broadcast (North America, Japan, parts of South America) (30000/1001).
- 30 / 50 / 59.94 / 60 high-framerate broadcasts and many gaming or screen capture recordings.
How to use
- Paste your SRT or VTT file into the input, or click Load file to read one from disk. The format is detected automatically.
- Pick the source framerate (the fps the subtitles were timed against) and the target framerate (the fps your video file plays at). Use a preset for the common NTSC and PAL conversions.
- If the file also has a few seconds of compound delay, set an extra constant offset, or use the anchor helper to compute it from one known line.
- Optionally limit the rescale to cues between two timestamps so only part of the file is touched.
- Check the before-and-after preview, then Copy output or Download the new SRT or VTT file.
About this tool
Subtitle Framerate Converter rescales the timestamps in SRT and WebVTT subtitle files when the source video framerate does not match the playback framerate. The most common cause is a 23.976 fps NTSC film source being played back as a 25 fps PAL re-encode (or the other way around): the captions line up at the very start of the video, then drift further apart from the audio the longer it runs. The fix is mathematical, not a constant offset. Every cue start and cue end has to be multiplied by the source-to-target framerate ratio so the gap between line one and line one hundred shrinks (or grows) by exactly the right amount. Paste an SRT or VTT file, pick a source framerate and a target framerate (23.976, 24, 25, 29.97, 30, 50, 59.94, or 60 are one click each, or type any positive value), and the rescaled file appears below ready to copy or download. Quick presets cover the four most common conversions in both directions. An optional extra constant offset handles compound problems where the file is also a few seconds off at the start, with an anchor helper that computes the residual offset for you from a single known line. An optional range limits the rescale to cues that start between two timestamps, useful when only part of the file was re-encoded. The parser preserves the WEBVTT header block, cue identifiers, and cue settings such as line:90% align:center, and renumbers SRT cues in order. A before-and-after preview shows every cue with the original and new times so you can verify the result. Negative-going cues are clamped at the start of the timeline with a per-cue warning. All parsing, math, and writing happen in your browser; nothing is uploaded.
Free to use. Works in your browser. No signup, no login.
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