Subtitle Timestamp Shifter
Use this page to adjust the file before you use it without installing anything. Everything happens in your browser, the work runs on your own copy of the file, and the result comes back as a separate download you can check before using.
Subtitle Timestamp Shifter
Result
The conversion runs in this page. Output claims are limited to the formats and browser capabilities shown here.
關於 Subtitle 轉換的常見問題
Will my original file be changed?
The result is downloaded as a separate file. Keep your original until you have checked the Result.
What should I check before using the result?
Open the Result in the application that consumes it and spot-check the parts that matter to you; the original file stays untouched if you need to re-run with different options.
Should I enter a positive or negative offset?
Use a positive value when the subtitles should appear later. Use a negative value when they should appear earlier.
Can it fix changing subtitle drift?
No. One offset handles a consistent difference. Changing drift needs a time-stretch or manual cue edit.
Can the first timestamp become negative?
Negative results are clamped at zero. Check the first cue after a large negative adjustment.
Can I rely on the result without checking it?
Review the preview and open the downloaded file in the tool that will use it. A conversion can be structurally successful while still needing a correction for layout, content, timing, color, or application-specific settings.
Subtitle Timestamp Shifter
A subtitle timestamp shifter is useful when every cue in an SRT or VTT file is consistently early or late. Instead of editing cue times one by one, this page applies one offset to every parsed start and end time. A positive number delays the subtitles. A negative number moves them earlier. The source text and cue order stay intact. The tool is suited to a consistent sync offset; it cannot correct a recording whose drift changes from the beginning to the end.
This page is built for a clear input-to-output task. It gives the browser a file or text value, applies the conversion described above, and leaves the result available for review before download. A successful file download does not mean that every application will interpret the result in the same way. The safest workflow keeps the source file, checks a representative section, and tests the output in the application or player that will receive it.
How to use
Upload an SRT or VTT file or paste the subtitle text. Enter the offset in seconds, including a decimal when the correction is smaller than one second. Check that the sign matches the problem you observed. Click Convert and compare the first, middle, and last cues with the video. Download the adjusted file only after checking that no cue moved below zero or past a useful playback point. Keep the original file so the adjustment can be reversed.
- Choose a supported input file or paste the supported text into the input area.
- Set the options shown for this tool and check that the input is the file type named on the page.
- Click Convert and read the output preview, status message, and any warnings.
- Download the result, then test it in the destination workflow before replacing the source.
Use cases
This tool fits video editors, course teams, localization reviewers, stream archive managers, and developers testing a caption track. It works well for a file that came from a recording with a fixed start delay, a player that begins captions at the wrong point, or a delivery export with one consistent offset. For variable drift, missing cues, or inaccurate transcription, use a subtitle editor with the video loaded and make a more detailed correction.
A small browser converter is a good fit for a one-off task, a sample file, a review handoff, or a format check. It is less suitable for an unattended batch pipeline when the file set is large or the output needs a strict schema, printer profile, codec guarantee, or audit trail. For those workflows, keep the mapping and validation rules in the system that owns the data.
Output format
The output keeps the detected SRT or VTT style and writes new timestamps after applying the selected offset. Cue text, identifiers, and supported settings remain in their existing order. Times are clamped at zero when a negative offset would create a negative timestamp. That behavior prevents an invalid beginning time, but it can shorten the first cue, so inspect the start of the result. The output is not a new video and does not change audio timing.
The expected result is .srt-vtt output or the downloadable result described on this page. Source-specific details can change when the input format has no direct equivalent for layout, metadata, styling, timing, searchable text, color, or codec behavior. Review the actual download instead of relying only on the file extension.
Privacy
The page processes the subtitle text in the browser and does not need a video upload. Subtitle text can still be confidential or licensed, so only use files you are permitted to edit. When a team handles unreleased media, test with a redacted copy and confirm the deployed site policy before using the result in a production workflow. Store the original separately if the adjustment needs to be audited later.
The page is designed around browser-side processing and does not require an AI API for the conversion described here. The site still loads page assets, and browser extensions, deployment settings, and organizational policy can affect a real environment. Do not use this wording as a legal privacy promise. Use the privacy policy and your own security review for confidential or regulated files.