What are ASS subtitles?
ASS (Advanced SubStation Alpha) is a subtitle format that stores the look together with the text. The file has a header, a list of styles with font, size, color and outline, and Dialogue lines with the timing of each line of speech. It is popular for fansubs, karaoke and players like VLC and mpv.
Also called: Advanced SubStation Alpha, SSA, .ass file
Part of an ASS file
The Default style sets the font, the size and the black outline. Each Dialogue line says when the text comes in and out and which style it uses. The \N forces a line break.
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, OutlineColour, Outline, Alignment
Style: Default,Arial,64,&H00FFFFFF,&H00000000,3,2
[Events]
Format: Layer, Start, End, Style, Text
Dialogue: 0,0:00:01.12,0:00:03.48,Default,I started filming in 2015.
Dialogue: 0,0:00:03.56,0:00:06.20,Default,At my first one,\NI forgot the vows.When ASS makes sense
When the captions need their own look and will play in a player that understands the format. ASS can place text in any corner, change color mid-sentence and animate words, none of which SRT can do.
The downside is compatibility: YouTube, Instagram and most editors ignore ASS styling. For social media, the safe route is burning the captions into the video, with the style already drawn into the image.
Styled captions in FilmScribe
We do not export ASS. Styled captions come burned into the clip's MP4, with 235 animated styles and 54 fonts, and the caption file comes as SRT or FCPXML. If a player needs ASS, the free tool converts your SRT, with the font, size, color and position you choose.
Convert SRT to ASS Pick the font, size, color and position and download an .ass file ready for Aegisub, VLC and mpv. Convert SRT to ASS →Working with ASS files without surprises
- 01
Match the script resolution
Font sizes and positions in ASS are measured against PlayResX and PlayResY in the header. If those do not match the video, captions come out too big, too small or in the wrong place.
- 02
Send the fonts along
The file only stores the font name. If the viewer's computer lacks that font, the player swaps in another and line breaks shift. Send the font files with the subtitles, or attach them inside an MKV.
- 03
Colors are written backwards
ASS colors use &HAABBGGRR: alpha first, then blue, green and red, with 00 meaning opaque. Pure red is &H000000FF, and &H00FF0000 is blue. Swapped colors are the classic styling mistake.
- 04
One style per role
Create a style for each recurring role, like Default, Host and Signs, instead of overriding tags line by line. Changing a style later updates every line that uses it and keeps the file readable.
Related terms
See all terms →Frequently asked questions
What is the difference between ASS and SSA?
SSA (SubStation Alpha) is the older version. ASS is the advanced version, with more styling and effect options. Current players read both, and .ass is the more common extension today.
Can I upload ASS subtitles to YouTube?
YouTube ignores ASS styling. Convert to SRT or VTT to get a caption track, or burn the captions into the video if the look is what matters.
What program edits ASS files?
Aegisub is the most widely used ASS editor. For simple changes any text editor works, since the file is plain text.
Captions, clips and paper edits. All in one place.
Upload a video or paste a YouTube link. We transcribe every word with its timing, and you take the result to social media or to your editor.
See the result on your own recording before adding a card.