Are my SUB files uploaded anywhere?

No. This conversion runs entirely inside your browser, so the file never leaves your device. You can confirm it yourself: open the network tab of your browser's developer tools and watch that nothing is sent while the file converts.

Is converting SUB to ASS free?

Yes, without a limit on how many files you convert and with no watermark on the result. Files up to 100 MB are covered by the free plan.

Does converting SUB to ASS lose quality?

No. ASS stores the same content without discarding anything, so the result is identical in quality to the original.

Do I need to install anything to open ASS files?

No installation is needed for the conversion itself — it runs in the browser you already have. Opening the ASS afterwards needs whatever software normally handles Advanced SubStation Alpha on your device.

SUBtoASS

Convert SUB to ASS

Up to 3 files at once, 100 with Pro. Mixed formats are fine.

You can convert SUB to ASS free and without an account: drop the file above and the ASS is ready to download in a second or two. The conversion happens inside your own browser, so the file is never uploaded — it works on Windows, Mac, Linux, iPhone and Android, and keeps working with the network switched off.

What SUB and ASS are for

Frame-based subtitles. Goes out of sync the moment the frame rate changes.

Subtitles with positioning, fonts and effects. Standard in anime fansubbing.

How to convert SUB to ASS

Drop your SUB file onto this page, or click to pick one.
Choose ASS as the target. The conversion runs inside your browser — the file is never uploaded.
Download the finished ASS file.

SUB vs ASS: what changes

SUB compared with ASS
	SUB	ASS
Full name	MicroDVD Subtitle	Advanced SubStation Alpha
File extension	.sub	.ass, .ssa
Media type	text/plain	text/x-ssa

Quality: Nothing is lost. The result holds exactly the same picture, text or data as the original.
Where it runs: This conversion runs inside your browser. Your file is never uploaded, and it works with the network disconnected.

SUB to ASS: common questions

Are my SUB files uploaded anywhere?: No. This conversion runs entirely inside your browser, so the file never leaves your device. You can confirm it yourself: open the network tab of your browser's developer tools and watch that nothing is sent while the file converts.
Is converting SUB to ASS free?: Yes, without a limit on how many files you convert and with no watermark on the result. Files up to 100 MB are covered by the free plan.
Does converting SUB to ASS lose quality?: No. ASS stores the same content without discarding anything, so the result is identical in quality to the original.
Do I need to install anything to open ASS files?: No installation is needed for the conversion itself — it runs in the browser you already have. Opening the ASS afterwards needs whatever software normally handles Advanced SubStation Alpha on your device.