Rescale subtitle timings when your video frame rate changes. Free, private, runs in your browser.
When a video is converted from one frame rate to another — for example 24 fps film sped up to 25 fps for European (PAL) broadcast — the picture moves faster, so subtitle timings must be stretched by the same ratio to stay in sync. This tool multiplies every cue start and end time by target FPS / source FPS. Pick the original video frame rate as the source and the new one as the target, upload your subtitle file, and download the rescaled version.
The most frequent use cases are 24 to 25 fps and 23.976 to 25 fps for PAL, 25 to 24 fps and 25 to 23.976 fps for the reverse, and 29.97 to 25 fps when NTSC material is converted to PAL. Using the exact fractional values like 23.976 and 29.97 matters — approximations cause timing drift that grows with the length of the video.
MicroDVD subtitles store frame numbers rather than timestamps. Instead of treating them as milliseconds, this tool scales the frame numbers directly by the FPS ratio and rounds to the nearest frame. If your .sub file contains an FPS hint line such as {1}{1}23.976, the source FPS is auto-detected when you upload it.
Upload multiple files at once, either individually or bundled in a .zip archive. Every supported subtitle file is rescaled with the same source and target FPS. Download each file separately or download a single ZIP containing all rescaled files. The output keeps the same format as the input, so an SRT stays an SRT and an ASS file keeps its styling and layout. If the subtitles need a constant offset instead of rescaling, use sync subtitles online after converting. Learn more in SRT vs VTT vs ASS explained and find test files in the movies library.
It multiplies every cue start and end time by the ratio of the new frame rate to the original (target FPS divided by source FPS). So converting 24 fps subtitles to a 25 fps video speeds up every timing by 25/24, keeping the subtitles locked to the picture.
SRT, WebVTT (VTT), ASS, SSA, SMI/SAMI and MicroDVD (SUB). The output keeps the exact same format as the input file. You can also upload ZIP archives containing multiple subtitle files for batch conversion.
Select 24 as the source FPS and 25 as the target FPS, then upload your subtitle file. Every timestamp is scaled by 25/24. This is the classic PAL conversion used when a 23.976 or 24 fps film is sped up to 25 fps for European television.
NTSC video runs at 29.97 fps and cinematic sources are often 23.976 fps rather than true 24 fps. Using the exact source value matters — a small error in the FPS ratio builds up into seconds of drift over a two-hour movie.
Yes. MicroDVD subtitles store frame numbers instead of timestamps, so the tool scales the frame numbers directly by the FPS ratio (it does not treat them as milliseconds). Choose the correct source FPS for the frame numbers to be accurate.
Timestamps are scaled to the nearest millisecond (frame numbers to the nearest frame), so precision is preserved as well as the format allows. For SRT and VTT that means millisecond precision, and for ASS/SSA centisecond precision.
No. Everything runs entirely in your browser. Your subtitle files never leave your device, which makes the tool safe for unreleased content.
Rescaling stretches the whole timeline by a fixed ratio — needed when the video frame rate changes. Shifting just moves every cue by the same offset — needed when subtitles are consistently early or late. Use this tool for the first case and the subtitle position/shift tool for the second.
Yes. Select multiple files or upload a ZIP archive. All supported subtitle files are processed with the same source and target FPS, and you can download each file individually or grab a single ZIP with all rescaled files.
That symptom usually means the frame rate changed (for example NTSC 29.97 to PAL 25). Set the original FPS as the source and the new FPS as the target in this tool, then download the rescaled subtitles.
VLC offers a subtitle delay but not true FPS rescaling. Rescale the subtitle file with this tool first, then load the output in VLC — the timing will match the new video frame rate.
Subtitle Edit can adjust frame rate with its resync tools, but it is desktop software. This tool does the same thing online in the browser without installation or uploads.
Drift that grows over time is almost always a frame rate mismatch rather than a fixed offset. If the audio gets ahead or behind progressively, rescale with the correct source and target FPS instead of shifting.
PAL video runs at 25 fps, so a 24 fps film is sped up by 25/24 (about 4 percent) when converted for European television. Subtitles authored for the original film must be rescaled by the same 25/24 ratio to stay in sync.
Use this subtitle FPS converter when you need to rescale every subtitle timestamp when the video frame rate changes. The workflow is browser-based and the output is downloaded to your device.
Supported input or output formats for this workflow are SRT, VTT, ASS, SSA, SMI, and MicroDVD SUB. The exact controls on the page determine which options apply.
This tool is designed for a focused subtitle workflow: rescale every subtitle timestamp when the video frame rate changes. It reads the selected subtitle data in the browser, applies the chosen operation, and creates a downloadable result without requiring a separate desktop editor.
Start with the file type described in the tool controls and check that it belongs to the video you are working with. Keeping the original file lets you compare the result if a player interprets formatting or timing differently.
After downloading, load the output beside the matching video and verify a cue near the beginning, middle, and end. This catches format-specific timing or player-support differences before you archive the file.
The tool is intended for local browser processing. Your selected subtitle content is handled by the page and the generated file is downloaded locally; it is not presented as a server-side editing workflow.
Open this tool, select the relevant file, choose the available subtitle FPS converter options, and download the generated result. The page keeps the workflow in the browser rather than requiring an installed editor.
Use the formats listed in the tool description and picker. SRT, VTT, ASS, SSA, SMI, and MicroDVD SUB Formats outside that list may be rejected or need conversion first.
The tool is built for browser-side processing. Your file is selected by the browser and the result is downloaded locally rather than being described as a server upload.
No. Subtitle tools create or modify subtitle output only. The video itself is not edited, re-encoded, or downloaded by this workflow.
Open the downloaded file with a text editor or your video player. Confirm that cues are present, timestamps make sense, and the filename matches the video when automatic loading is useful.
Confirm the extension and file contents, then try a supported format such as SRT or VTT. If the file is an image subtitle or a video container, use the matching extraction or OCR tool instead.
Compatibility depends on the player and output format. SRT is a practical choice for broad device support, while WebVTT is intended for HTML5 video and browser-based players.
Yes. The workflow creates a separate download. Keeping the source is useful when you need to repeat the operation with different settings or preserve styling that an output format cannot store.