Convert Subtitles to ASS
Convert SRT, VTT, ASS and any other subtitle file to Advanced SubStation Alpha (ASS) for free in your browser. Batch convert to ZIP.
How it works
- 1
Drop one or more files into the box above.
- 2
Pick the output format (already chosen on dedicated pages).
- 3
Download each file or everything as a ZIP. Nothing is uploaded.
Frequently asked questions
Is Convert Subtitles to ASS free?
Yes. Every tool on FastSub AI is free, with no sign-up, no watermark and no usage limits.
Are my files uploaded anywhere?
No. Your files are read and processed inside your browser tab. The only downloads are the app itself and, for AI tools, the model files.
Which subtitle formats are supported?
SRT, WebVTT, ASS/SSA, SBV, SUB (MicroDVD), SAMI, TTML/DFXP, LRC and CapCut projects in; all of those plus TXT, CSV, JSON, FCPXML, Word and PDF out.
Is there a file size limit?
Subtitle files up to 20 MB and videos up to several GB, limited only by your device's memory.
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