Subtitle FPS Converter

Free browser tool · Nothing uploaded · Updated August 4, 2026

Fix subtitles that drift further and further out of sync because they were made for a different frame rate. Pick the source and target frame rate and every timestamp is rescaled proportionally. Common when a subtitle made for 23.976fps film is used on a 25fps (PAL) copy. Runs entirely in your browser.

🔒 100% local. Your file is processed in your browser and never uploaded.
Drop your .srt file here, or click to choose
Everything stays on your device.

— or paste the subtitle text below —

Source frame rate
Target frame rate
Extra offset (ms, optional)

Why do subtitles drift out of sync over time?

When a subtitle file was timed for one frame rate but the video plays at another, the mismatch compounds: the subtitles start roughly right and get progressively more wrong toward the end. The classic case is film mastered at 23.976 or 24 fps and released on PAL at 25 fps, which plays about 4% faster. This tool multiplies every timestamp by source÷target frame rate to line them back up.

Which frame rates should I choose?

Pick the frame rate the subtitles were made for as the source, and your video's frame rate as the target. Common pairs are 23.976 ↔ 25 (NTSC film to PAL) and 25 ↔ 23.976 (PAL back to film). If you are unsure, try one conversion, check the first and last lines against the video, and reverse if needed. A small constant offset field is available for fine-tuning.

Frequently Asked Questions

What frame rates are supported?

The presets are 23.976, 24, 25, 29.97, and 30 fps, plus a custom value for anything else.

Should I use this or the shifter?

Use the FPS Converter when subtitles drift more and more over time (a frame-rate mismatch). Use a constant shift when they are off by the same amount throughout.

Does it change the subtitle text?

No. Only the timestamps are rescaled; the text is untouched.

Is my file uploaded?

No. Everything runs in your browser and the file never leaves your device.

See all free subtitle tools.

Working with subtitles at scale?

These free tools handle files you already have. GeekLink extracts hardcoded subtitles via OCR, transcribes and translates with AI, and burns subtitles into video — batch-processing dozens of videos, all locally on your Mac or Windows PC.

Try GeekLink Free