SRT, VTT and ASS are the three subtitle formats you meet most. Converting between them is easy once you know what each one keeps, and most “strange characters” problems come from encoding, not from the format.
SRT vs VTT vs ASS in one minute
- SRT: the simplest and most widely supported. Index, timecode, text. Basic italics at most.
- VTT (WebVTT): the web standard for HTML5 video players and many platforms. Almost the same as SRT, with a
WEBVTTheader and dots instead of commas in times. - ASS: rich styling (fonts, colors, positions, karaoke effects). Popular for anime and stylized captions.
SRT to VTT
By hand: add WEBVTT and a blank line at the top, then change the commas in timestamps to dots (00:00:01,000 → 00:00:01.000). With ffmpeg:
ffmpeg -i input.srt output.vtt
SRT to ASS and back
ffmpeg -i input.srt output.ass
Going from ASS to SRT drops all styling: positions, colors and effects are lost, only the text and times remain. Keep the ASS original if the styling matters.
Fixing strange characters
If you see é instead of é, question marks instead of Chinese, or boxes instead of Arabic, the file is not saved as UTF-8. Older files are often in Windows-1252, Windows-1251, GBK or Big5. Open the file in Notepad++ or Subtitle Edit, choose the right original encoding until the text looks correct, then save it as UTF-8. Or let the free fix subtitle encoding tool detect it for you.
Do it in the browser, without uploading
Our free subtitle tools convert between SRT, VTT, ASS, SBV, SUB, TXT and CSV, fix encoding, shift times, and merge or split files. They run in your browser, so the file never leaves your computer.
Subtitles inside a video file?
If the subtitles are a track inside an MKV or MP4, first take them out with the free MKV/MP4 subtitle extractor, then convert.