Online Batch Subtitle Time Shifter

Easily batch adjust subtitle timing. Simple, safe, and processed locally in your browser!

Positive value delays subtitles, negative value advances themSupported formats: .srt, .vtt, .webvtt, .ass, .ssa, .smi, .sami

FAQ / User Guide

  1. Which subtitle formats are supported?
    Currently supports .srt, .ass, and .vtt formats. Please make sure your files are UTF-8 encoded to avoid garbled text.
  2. How to batch shift multiple subtitle files?
    Click "Folder Upload" to select a folder with multiple subtitle files. The tool will process each file and allow you to download all results as a zip. Note: Only files in the root folder will be processed, subfolders will be automatically filtered out.
  3. How do I advance or delay subtitles by a few seconds?
    Enter a positive number (delay) or negative number (advance) in the "Offset" input. The unit is milliseconds. For example, -2500 means advance by 2.5 seconds.
  4. How do I save the shifted subtitles?
    After processing, download links will be generated automatically. You can download each file or download all as a zip if you uploaded a folder.
  5. How does the tool handle subfolders?
    When you upload a folder, the tool will automatically detect subfolders but only process files in the root folder. Files in subfolders will be filtered out to avoid processing unwanted files.
  6. Why are my subtitles garbled after shifting?
    Please check if your subtitle files are UTF-8 encoded. If not, use a text editor (like VS Code or Notepad++) to convert them to UTF-8 before uploading.
  7. Will the subtitle content be changed?
    Only the timestamps will be shifted. The subtitle text itself will not be modified.
  8. Can I set a custom offset for each subtitle line?
    Currently, only a uniform offset is supported. For advanced editing, please use professional subtitle editors (e.g., Aegisub).
  9. Is this tool safe? Will my files be uploaded?
    All processing is done locally in your browser. No files are uploaded or stored on any server.
  10. My shifted subtitles are not synced in the player?
    Please double-check the offset value and make sure your player is loading the shifted subtitle file.
  11. Can I use this tool on my phone?
    This tool works on mobile browsers, but for best experience, we recommend using it on a computer.