How to Convert SUB to ASS — Quick & Free
Fast, instant SUB (MICRODVD) to ASS (ADVANCED SSA) conversion. No signup required. Just drop your .sub file and get .ass in seconds.
Batch Settings
About SUB (MICRODVD) to ASS (ADVANCED SSA) Conversion
Short answer: yes, you can convert SUB to ASS online for free, and quality is well preserved with the right settings. Just upload your .sub file to CocoConvert, pick ASS as the output, and click Convert. The whole process takes seconds.
Now for the details. SUB is a widely used file format. ASS (Advanced SubStation Alpha) supports styled subtitles with fonts, colours, and positioning. Converting between these two formats lets you convert between formats quickly.
Your SUB file is decoded and re-encoded as ASS. Converting SUB to ASS maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert runs entirely online — no software to install, no account to create. Your files are encrypted during upload (TLS), processed on isolated servers in Germany, and permanently deleted after 24 hours. It works in Chrome, Safari, Firefox, Edge, and all mobile browsers.
Need to convert more than one file? Free users can do 5 per hour. Pro gets 100 per hour with files up to 5 GB each.
How to Convert SUB (MICRODVD) to ASS (ADVANCED SSA)
- 1
1. Upload SUB
Drop your .sub file onto the page (or tap "Browse" on mobile). Add multiple files for batch conversion.
- 2
2. Select ASS
Choose .ass from the output dropdown. Settings are pre-configured for best results.
- 3
3. Convert
One click. The server handles all the heavy lifting using FFmpeg and Sharp.
- 4
4. Download
Your .ass file is ready. Download it directly or get all files as a zip archive.
What Happens When You Convert SUB (MICRODVD) to ASS (ADVANCED SSA)
Your SUB file is decoded and re-encoded as ASS.
Your SUB file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in ASS format
The converted file is ready for download
Format Comparison
SUB (MicroDVD)
.sub file
| Extension | .sub |
| MIME Type | text/x-sub |
| Category | Subtitle / Caption |
ASS (Advanced SSA)
.ass file
| Extension | .ass |
| MIME Type | text/x-ass |
| Category | Subtitle / Caption |
Should You Convert SUB (MICRODVD) to ASS (ADVANCED SSA)?
When to Convert
- ✓When you need a ASS file
Frequently Asked Questions
Is SUB to ASS conversion free?
Yes. CocoConvert offers free SUB to ASS conversion with generous daily limits — 25 minutes of processing time and up to 5 files per hour (250 MB each). Pro plans remove these limits.
How fast is SUB to ASS conversion?
Most files convert in 2–10 seconds depending on size. Large subtitle / caption files may take 30 seconds. Batch jobs process in parallel for maximum speed.
What happens to my files after conversion?
Your uploaded SUB file and the converted ASS file are both automatically deleted from our servers within 24 hours. They are never shared, sold, or analysed.
Does converting SUB to ASS lose quality?
Converting SUB to ASS maintains high quality with CocoConvert's optimised encoder settings.
Can I convert ASS back to SUB?
Yes, CocoConvert supports ASS to SUB conversion as well. However, if the original conversion involved lossy compression, converting back won't recover the lost data.