YAML Validator
Check YAML syntax and pinpoint the exact error.
Processed locally in your browser. Nothing you enter is uploaded or stored.
- Parses with the same YAML library the YAML ↔ JSON converters on this site use, so "valid here" means it will actually convert.
- Points at the exact line and column of the first error — YAML's indentation-sensitivity makes this especially hard to spot by eye.
- Runs in your browser; config isn't uploaded.
Why this is private
- Processed locally in your browser. Nothing you enter is uploaded or stored.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Checks whether YAML is syntactically valid — indentation, anchors, block/flow structure — and reports the exact line and column of the first error.
How to use it
- 1Paste YAML.
- 2Validation runs automatically as you type.
- 3If invalid, the exact error position and reason are shown.
Tips
- Mixing tabs and spaces for indentation is one of the most common YAML errors and one of the hardest to spot visually — if the reported line looks fine, check its indentation character by character.
Frequently asked questions
What people use it for
Debug a CI pipeline that won't parsePaste your GitHub Actions/GitLab CI YAML to find the exact indentation or syntax break.
Check a Kubernetes manifest before applying itCatch a YAML syntax error before `kubectl apply` does.
Verify config pasted from docs or a chatPasted YAML often loses indentation — this points straight at the break.
Related guides
- How to read JSON with a tree viewerA tree viewer turns a wall of brackets into a structure you can expand, search and copy paths from. Here's how to use one effectively.
- JSON parse errors explained: 'Unexpected token', 'Expected comma or brace', and the restWhat each common JSON error message actually means, the usual cause, and how to find the spot fast using line and column.
- How to format JSON (and actually understand the errors)JSON looks like a JavaScript object but follows stricter rules. Here's what those rules are and how to read the errors when they're broken.
Related tools
All developer toolsReady to use YAML Validator?
YAML Validator