Validate ASS / SSA before you ship
Strict ASS / SSA validator catches malformed timestamps, encoding glitches, and spec violations before your file lands at a fussy player or distribution platform.
Input
ASS / SSA file
Drop, paste, or pick
Output
Pass / fail report
Errors with line numbers
- Runs 100% in your browser — nothing uploads
See it in action
ASS / SSA validator report
What you put in → what you get back
ASS / SSA input (with intentional errors)
What you provide
[Script Info] ScriptType: v4.00+ [V4+ Styles] Format: Name, Fontname, Fontsize, … Style: Default,Arial,24,&H00FFFFFF,… [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,0:00:12.34,0:00:15.78,Default,,0,0,0,,Hello, it's me Dialogue: 0,0:00:15.78,0:00:19.20,Default,,0,0,0,,I was wondering if after all
Validation report
What you receive
✓ Valid ASS / SSA Format : ASS / SSA Cues : 3 Encoding : UTF-8 Timestamps: monotonic ✓ Required fields: present ✓ Ready to ship.
Step-by-step guide
How to use this tool
- 01
Drop or paste ASS / SSA
Either input works — drag in a file, paste from clipboard, or type directly.
- 02
Strict parser runs
We check every timestamp, encoding, and required field against the spec.
- 03
Read the error report
If valid, you get a green check. If not, we list each error with line numbers — no guesswork.
Key features
Why use this tool
Spec-strict parser
We follow the ASS / SSA reference grammar — any deviation is flagged.
Helpful error messages
Each error names the line number and what's wrong, not just 'parse failure on line 42'.
Privacy-first
Validation runs in your browser. Use it on unreleased subtitles without leaking them anywhere.
Format mismatch detection
Pasted SRT into the ASS / SSA validator? We'll suggest switching to the right one before you waste time debugging.
Common use cases
Who this tool is for
Pre-delivery QA
Catch broken subtitles before sending to a client or platform that will reject the whole batch.
Player crash debugging
When a player rejects a file with a generic error, validate here to find the actual offending line.
Mass-cleanup
Identify which files in a folder need fixing — drop each one in for a fast pass/fail.
Questions answered
Frequently asked questions
Found errors? Fix them in seconds
Convert, repair, or re-time using one of our other tools.