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Subtitle Speed Converter

Match your subtitle file to a faster or slower video. Choose the video speed, preview the new timing, then download the synced file.

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Upload subtitle file
Supports SRT, VTT, ASS, and SSA. Processing stays in your browser.

Choose the speed used for your video, such as 1.25x or 0.8x. Check the preview before downloading.

Video speed: 1.250x
Subtitle timing preview
Compare the first 20 original cues with the timing matched to your selected video speed.
Upload a subtitle file to see how its timing will match the new video speed.

Keep subtitles in sync at the new video speed

Use this tool after speeding up or slowing down a video. Choose the video speed, review the updated subtitle timing, and download a file that is ready to play.

Choose the new video speed

Select 1.25x, 0.8x, or enter the exact speed used for your video.

Keep every cue in step

The full subtitle timeline is adjusted together, from the opening cue to the final line.

Private browser processing

Your subtitle file stays on your device while timings are adjusted.

Preview and download

Review the first cues before downloading the adjusted subtitle file.

Match subtitle timing to 1.25x, 0.8x, or any video speed

Use this tool after speeding up or slowing down a video. Select the video speed, check the preview, and download subtitles whose timing matches the new playback timeline.

Example input and output

Original timing
1 00:00:10,000 --> 00:00:13,000 A subtitle cue.
Timing for 1.25x video
1 00:00:12,500 --> 00:00:16,250 A subtitle cue.

Best for

Match a changed video speed

Sync subtitles after changing a video to 1.25x, 0.8x, or another playback speed.

Adjust the whole subtitle track

Every cue is retimed together, so subtitles stay in step from the opening line to the end credits.

Keep subtitle files private

SRT, VTT, ASS, and SSA files are parsed and adjusted locally in the browser.

Common file issues handled

Choose the video speed

Select a preset such as 1.25x or 0.8x, or enter the exact speed used for the video.

Preview before downloading

Compare original and adjusted timestamps before downloading, especially when using a custom speed.

Keep the source format

SRT, VTT, ASS, and SSA subtitle timing is adjusted while the original file format is kept where possible.

Frequently Asked Questions

How do I sync subtitles after changing video speed?
Upload the subtitle file, choose the speed used for your video, review the preview, and download the synced copy.
How do I adjust subtitles for 1.25x or 0.8x video?
Choose 1.25x or 0.8x, check the updated timestamps in the preview, then download the adjusted subtitle file.
Which formats are supported?
SRT, WebVTT, ASS, and SSA files are supported. The original format is preserved when possible.
Is my subtitle uploaded?
No. Parsing, preview, and timing adjustment happen locally in your browser.