ASS to SSA
Or paste subtitle text
What this conversion changes
Nothing is lost in this direction — every feature of the source format has somewhere to go in the target format.
This list comes from the capability matrix for these two formats, not from the particular file you loaded. A specific file may lose more if it uses features the format allows but the matrix does not model.
ASS and SSA are two dialects of the same scripting language. The newer one, Advanced SubStation Alpha, declares itself as ScriptType v4.00+ and keeps its styles in a V4+ section; the original declares v4.00 and keeps them in a V4 section. The Dialogue lines, the override codes and the timing notation are shared, so this conversion is a rewrite of the header rather than a translation of the subtitles.
The work is in the style table, because the columns differ between the dialects. The colour columns are where it shows: V4+ has separate outline and shadow colours, while V4 calls them tertiary and back. The converter reads your file by the column list it declares, then writes the column list the target dialect expects, carrying each value to the matching column. The section heading and the declared script type are updated too — a file that claims v4.00+ while using V4 columns is rejected by most renderers.
Nothing about your timings or text changes, and the conversion runs entirely in your browser.
Examples
A typical ASS file, converted to SSA
Input
[Script Info]
Title: Example
ScriptType: v4.00+
WrapStyle: 0
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1
Style: Title,Arial,36,&H0000FFFF,&H000000FF,&H00000000,&H00000000,-1,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Hello there.
Dialogue: 0,0:00:05.00,0:00:08.50,Default,,0,0,0,,{\i1}Italic{\i0} and {\b1}bold{\b0} text.
Dialogue: 0,0:00:09.00,0:00:12.00,Title,,0,0,0,,{\pos(320,240)}Positioned
Dialogue: 0,0:00:13.00,0:00:16.00,Default,,0,0,0,,{\k50}ka{\k30}ra{\k20}o{\k10}ke
Dialogue: 0,0:00:17.00,0:00:20.00,Default,,0,0,0,,Line one\NLine two
Dialogue: 1,0:00:21.00,0:00:24.00,Default,,0,0,0,,{\an7}Top left
Output
[Script Info]
Title: Example
ScriptType: v4.00
[V4 Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, TertiaryColour, BackColour, Bold, Italic, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, AlphaLevel, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,,&H00000000,0,0,1,2,2,2,10,10,10,,1
Style: Title,Arial,36,&H0000FFFF,&H000000FF,,&H00000000,-1,0,1,2,2,2,10,10,10,,1
[Events]
Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Hello there.
Dialogue: 0,0:00:05.00,0:00:08.50,Default,,0,0,0,,{\i1}Italic{\i0} and {\b1}bold{\b0} text.
Dialogue: 0,0:00:09.00,0:00:12.00,Title,,0,0,0,,{\pos(320,240)}Positioned
Dialogue: 0,0:00:13.00,0:00:16.00,Default,,0,0,0,,{\k50}ka{\k30}ra{\k20}o{\k10}ke
Dialogue: 0,0:00:17.00,0:00:20.00,Default,,0,0,0,,Line one\NLine two
Dialogue: 0,0:00:21.00,0:00:24.00,Default,,0,0,0,,Top left
Nothing is dropped here: compare the two sides line for line.
The same conversion on an awkward input
Input
[Script Info]
; 一份真实的脏文件：BOM + CRLF + 认不出的覆写码 + Comment + 坏时间码
Title: Dirty sample
ScriptType: v4.00+
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,1,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1
[Fonts]
fontname: Arial
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Comment: 0,0:00:00.00,0:00:01.00,Default,,0,0,0,,这是一条注释，不该变成字幕
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Hello, world
Dialogue: 0,0:00:05.00,0:00:08.00,Default,,0,0,0,,{\fad(300,300)}Unmodelled override
Dialogue: 0,0:00:09.00,0:00:12.00,Default,,0,0,0,,{\an7\pos(320,240)}Both, wrong order
Dialogue: 0,0:00:13.00,0:00:16.5,Default,,0,0,0,,One decimal centisecond
Dialogue: 0,0:00:17.00,0:00:20.00,Default,,0,0,0,,Soft\nbreak
Dialogue: 0,0:00:xx.00,0:00:24.00,Default,,0,0,0,,Broken timecodeOutput
[Script Info]
Title: Dirty sample
ScriptType: v4.00
[V4 Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, TertiaryColour, BackColour, Bold, Italic, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, AlphaLevel, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,,&H00000000,-1,0,1,2,2,2,10,10,10,,1
[Events]
Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Hello, world
Dialogue: 0,0:00:05.00,0:00:08.00,Default,,0,0,0,,{\fad(300,300)}Unmodelled override
Dialogue: 0,0:00:09.00,0:00:12.00,Default,,0,0,0,,{\pos(320,240)}Both, wrong order
Dialogue: 0,0:00:13.00,0:00:16.50,Default,,0,0,0,,One decimal centisecond
Dialogue: 0,0:00:17.00,0:00:20.00,Default,,0,0,0,,Soft\Nbreak
This is the kind of damage real files have — mixed line endings, stray whitespace, fields left empty. Compare it with the tidy example above to see what the parser forgives.
Frequently asked questions
What actually differs between ASS and SSA?
The style table's column list, the script type line and the heading of the styles section. Dialogue lines, override codes and timestamp syntax are shared, which is why a script can be converted between the dialects without touching a single cue.
Does my outline colour survive?
Yes. The V4+ outline column and the SSA tertiary column hold the same kind of value in the same kind of place; only the name in the header row changes. The converter maps one to the other rather than dropping either.
Will the output still play in an older player?
That is usually why people convert this way. The output declares the older script type and uses the older styles section, which is what those renderers expect. A newer file loaded by an older player typically shows the dialogue but ignores all the styling.
Are the timings touched?
No. Both dialects write time as hours, minutes, seconds and hundredths, so every timestamp is copied across unchanged and the subtitles stay in sync with the same video.
What if my file uses columns from the other dialect?
It is read by the column list declared in the file, not by position. Whatever order the columns are in, the values are matched to the right roles, and the output is written in the order the target dialect specifies.