YAML validator
Check a YAML file (Docker Compose, GitHub Actions, Kubernetes…): indentation, duplicate keys, syntax. Error pinpointed to the line. Nothing is uploaded.
Accepted: JSON, CSV, TSV, XML, YAML, YML, TXT · Max 50 MB per file
Processed on your device — nothing is uploaded.
Tip: paste text anywhere on the page (Ctrl+V).
How to validate YAML
Paste your YAML or drop the .yml file.
The verdict appears at once, with the line and column of the error.
Fix it in the box; the normalised version on the right can be copied or downloaded.
Why use this tool
- Instant verdict
- Valid or not, with the number of items, columns and nesting depth. YAML also reports duplicate keys.
- Errors explained
- A missing comma, a badly closed tag, wrong indentation: the line and column are shown, the line is highlighted and “Go to error” puts the cursor there.
- One-click repair
- Comments, trailing commas, single quotes, unquoted keys: the most common slips in hand-written JSON are fixed automatically.
- Nothing leaves your device
- The conversion runs in your browser: your data is never sent to a server, even 50 MB files.
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