About this tool
When subtitles run ahead of or behind the audio by a constant amount, the fix is to shift every cue by the same offset. Enter the number of seconds, positive to delay the subtitles or negative to bring them forward, and the tool rewrites all the timestamps while keeping the file in its original format.
Everything happens inside your browser. Your file is never uploaded to a server: the conversion runs on your own device using WebAssembly, and the result is downloaded straight from memory. Close the tab and nothing is left behind.
How to use it
- Drop your SRT files into the box above, or click to browse. Nothing is uploaded.
- Adjust the options if you want; the defaults suit most files.
- Click the button and wait a moment.
- Download the results individually or all at once as a ZIP.
Frequently asked questions
The subtitles drift more and more over time. Does this fix that?
No. Drift means the frame rate of the subtitles and the video differ; that needs a stretch, not a shift. A constant offset is what this tool corrects.
Is the styling kept?
Formatting tags are removed so the text is clean; timing and line breaks are preserved exactly.
What is the difference between SRT and VTT?
SRT is the older, simplest format that media players expect. WebVTT is the web standard for the HTML video element and platforms like YouTube; the timing syntax differs slightly.
Is this really free?
Yes. The site is supported by ads, and there are no limits on how many files you convert.
Are my files uploaded anywhere?
No. The converter runs entirely in your browser. Files stay on your device, which also makes it faster than upload-based converters for anything larger than a few megabytes.
Is there a file size limit?
The only limit is your device's memory. Images and audio of any normal size are fine; for video, files under about 500 MB work well on most laptops and phones.
Which browsers are supported?
Current versions of Chrome, Edge, Firefox, and Safari on desktop and mobile. Very old browsers without WebAssembly support will not work.