Validator
ASS Validator
Check a Advanced SubStation Alpha (ASS / SSA) for malformed timestamps, broken cue structure and out-of-order timings before a player or platform rejects it. Runs entirely in your browser.
- Nothing is uploaded
- No account needed
- .ass
Result
Nothing to check yet
Paste a ASS file on the left, drop a .ass onto it, or load the sample. Results appear here as you type — there is no button to press.
What the validator checks
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.
What people use it 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.
Once it validates
Questions
What does the ASS validator check?
Structure and timing: that cues parse, that timestamps are well-formed and in a sensible order, and that the file's required blocks are present. It reports problems — it does not rewrite your file.
My file plays fine but shows errors. Why?
Players are forgiving and often guess past malformed cues. Another tool in the chain — an encoder, a platform's ingest, a different player — may not be. The validator reports what the specification requires, not what one player tolerates.
Is my file uploaded anywhere?
No. Validation runs entirely in your browser; the file never leaves your device.