Convert subtitles and fix sync

How to use

1. Drop a subtitle file (.srt, .vtt, .smi) in the area above. You can also copy the subtitle text and paste it with Ctrl + V.
2. Choose the output format (SRT or VTT).
3. If the subtitles appear later than the video, shift them by a negative value. If they appear earlier, shift them by a positive value. The list shows the new times right away.
4. Click Save subtitles. The file is saved as UTF-8, so characters display correctly in any player.

SRT vs. VTT

SRT is the most widely used subtitle format. It works in video players and on YouTube. VTT (WebVTT) is required by the <video> tag in web browsers and by some course platforms. The two formats differ only in the time notation (comma vs. period) and the header, so you can convert between them without losing content.

SMI subtitles and broken characters

Many old SMI files use legacy Korean or Japanese encodings (EUC-KR, Shift_JIS), so characters break in modern software. This tool detects the encoding automatically. If an SMI file contains more than one language, you can choose which language track to convert.