Free Online SRT & VTT Subtitle Sync Tool
Nothing ruins a good movie night or a YouTube video more than an out-of-sync subtitle. When the text appears seconds before or after the actor speaks, it breaks the immersion entirely. Our free subtitle time shifter is a professional client-side utility designed to fix subtitle delays instantly.
Because this tool is built using offline browser processing, you do not need to upload your heavy SRT or VTT files to a server. Simply paste the text, adjust the timeline, and download the corrected version securely in milliseconds.
How to Fix Out-of-Sync Subtitles:
- Open Your File: Open your corrupted `.srt` or `.vtt` file using a basic text editor (like Notepad on Windows or TextEdit on Mac) and copy all the text.
- Paste the Subtitle: Paste the copied text into the "Original Subtitle" box above.
- Set the Delay: Enter the time difference in milliseconds (1 second = 1000 ms). You can use our common presets for quick adjustments.
- Choose Direction: Select Forward if the subtitles are appearing too early (delaying them), or select Backward if they are appearing too late (speeding them up).
- Sync & Download: Click "Sync Subtitle". Review the results in the right panel and click Download to save your newly synced file.
Supported Subtitle Formats
Our regex parsing engine natively supports standard SubRip (SRT) timestamps formatted as HH:MM:SS,mmm as well as Web Video Text Tracks (VTT) formatted as HH:MM:SS.mmm or MM:SS.mmm. The algorithm intelligently calculates time rollovers, ensuring that if you add 5 seconds to 00:00:58, it correctly formats the new timestamp to 00:01:03 without breaking the script execution.