YAML Formatter
Format, lint and validate YAML files
YAML Formatter cleans up indentation and spacing in a YAML document and checks it parses correctly — catching the indentation mistakes that are YAML's most common source of broken config files, since unlike JSON, YAML's structure is defined entirely by whitespace.
How to use YAML Formatter
- 1
Paste your YAML content.
- 2
Click "Format" to clean up indentation and spacing.
- 3
Check the validation result confirms it parses correctly.
- 4
Copy the formatted YAML.
Everything you need to know about formatting YAML
Why YAML formatting matters more than most formats
YAML uses indentation itself to define structure — unlike JSON's brackets, a single misplaced space can silently change what a YAML file means, or break it outright. A formatter/linter catches these indentation issues before they cause a confusing failure in whatever's consuming the file (commonly CI/CD configs, Kubernetes manifests, or Docker Compose files).
When you actually need this
- Validating a CI/CD pipeline config before pushing it, since a YAML indentation error often fails silently or confusingly.
- Cleaning up inconsistent indentation in a config file edited by multiple people.
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Frequently Asked Questions
Why is YAML so sensitive to indentation?
Unlike JSON, which uses braces and brackets to show structure, YAML relies entirely on indentation level to show nesting — a single misplaced space changes what a document means, or breaks it outright. Consistent formatting is what prevents this.
What does validation actually check?
Whether the document parses as valid YAML at all — not whether it matches a specific schema your particular tool (like Docker Compose or GitHub Actions) expects. A file can be valid YAML and still be wrong for its intended use.
Can tabs be used for indentation in YAML?
No — the YAML specification doesn't allow tab characters for indentation, only spaces. A file with tabs will fail to parse, which this tool will flag as invalid.
Does this tool send my content to a server?
Yes — it's sent to our servers to format and validate, and the result is returned to you; nothing is stored.
Is this tool free to use?
Yes — completely free, with no signup and no usage limits for casual use.