VTT to SSA
Or paste subtitle text
What this conversion changes
2 things are dropped or need a decision
- Precision
timing precision — the output's clock is coarser, so every timestamp is rounded to the nearest 10 ms
- Format-specific content
content the source format keeps outside its cues (non-cue blocks, header text, per-cue settings, commented-out events) — the target format has no place for it
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.
This page converts VTT to SSA. Drop a file in — or paste the text — and you get the SSA version back. The conversion runs entirely in your browser, so nothing is uploaded and no account is needed.
These two formats do not store the same things, and the difference is not cosmetic: precision and format-specific content have nowhere to go in SSA. The list above comes from what the two formats can each express rather than from your file, so it is the same answer before you load anything.
One file is fine, and so is a whole season: the queue works through them in order and the results come down together as a single ZIP.
Examples
A typical VTT file, converted to SSA
Input
WEBVTT
intro
00:00:01.000 --> 00:00:04.000
Hello there.
00:00:04.500 --> 00:00:08.000 align:start position:10%
Second line with <i>italics</i>.
Output
[Script Info]
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,&H00000000,0,0,1,2,2,2,10,10,10,0,1
[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: 0,0:00:04.50,0:00:08.00,Default,,0,0,0,,Second line with {\i1}italics{\i0}.
Dropped in this output: precision and format-specific content. Everything else matches line for line.
The same conversion on an awkward input
Input
a stray comment line
cue-id-1
00:00:01.000 --> 00:00:02.000
No header, two lines before the timecode.
Output
[Script Info]
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,&H00000000,0,0,1,2,2,2,10,10,10,0,1
[Events]
Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:02.00,Default,,0,0,0,,No header, two lines before the timecode.
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
Why have the timestamps moved from VTT to SSA?
SSA stores time as `0:00:04.13` where VTT stores it as `00:00:04.126` — a hundredth of a second against a thousandth — so every timecode is rounded to the nearest 10 ms: 00:00:04,126 comes out as 4.13 seconds. Nothing is stretched or reordered and no cue moves by more than 5 ms, but if you are lining these subtitles up against another file, that is the one place this conversion stops being exact.
What happens to VTT's NOTE, STYLE and REGION blocks in SSA?
They are dropped. A WebVTT file can carry a header, comments, a style block, region definitions and per-cue settings such as `align` or `position`, and SSA has nowhere to put them — it stores cues, not a document. The cues themselves, text and timings, come through whole.
What does the output look like when VTT becomes SSA?
Like SSA: no cue numbers: every subtitle is a `Dialogue:` line in the `[Events]` section, with a `Marked` field where SRT keeps the number. Every VTT cue becomes one SSA cue, in the same order, with the same text.
How does a two-line VTT cue come out in SSA?
As two lines with `\N` between them, which is how SSA writes a hard line break. The pairing survives — the two VTT lines still belong to one subtitle in the SSA output, and a player shows them together.
Do VTT cues keep their order in the SSA output?
Yes, and they are sorted by start time on the way — earliest first, which is how every format here expects them and how players read them. If your VTT file listed its cues out of sequence, the SSA output puts them back in order; that is a change to the file's structure rather than its content, and it is deliberate.
Can I convert the SSA back to VTT?
Yes, and it has its own list: converting SSA to VTT drops styling, positioning, karaoke and format-specific content. That list is different from the one above because the two formats keep different things.
Does the SSA output keep the VTT file's encoding?
No — the output is UTF-8, with Unix line endings and no byte-order mark, whatever the VTT file used. A file that arrives in UTF-16, or in a Windows single-byte encoding, is decoded on the way in (the result panel says so when that happens); what comes out is always the same UTF-8 SSA.