YAML Formatter
Format YAML text for cleaner reading.
Format YAML text for cleaner reading.
Related tools
Ready tools are shown first.
Tool guide
Free Online YAML Formatter
Format YAML by parsing it into data and serializing it back to readable YAML. This browser-first formatter is useful for clean configuration output, but parse-and-stringify formatting may change comments, quotes, scalar styles, aliases, and other source-level details.
Steps
How it works
- Paste YAML or choose one YAML, YML, or TXT file.
- Run the formatter to parse the document with the installed YAML library.
- Review the serialized YAML output for source-level changes.
- Copy the result or download a formatted YAML file.
Highlights
Key features
- Uses the YAML library to parse and stringify one YAML document.
- Produces consistent library-managed indentation and scalar formatting.
- Works with pasted YAML and supported YAML, YML, or TXT files.
- Rejects input that cannot be parsed as YAML.
- Provides copy and YAML download actions.
Use cases
Common uses
- Clean up YAML configuration for easier reading.
- Normalize compact or inconsistently spaced YAML.
- Prepare readable YAML examples for documentation.
- Check a YAML file while producing a newly serialized copy.
Notes
Limitations to know
- There is no indentation selector; formatting uses the YAML library's default output style.
- Comments, directives, quote choices, block scalar styles, anchors, aliases, and merge-key representation may be lost or rewritten after conversion to plain JavaScript data.
- Multiple YAML documents are not supported by the single-document parse operation.
- Key order generally follows parsed JavaScript object order, but exact source order or representation is not guaranteed.
- Formatting does not repair invalid YAML or validate Kubernetes, Docker Compose, OpenAPI, or other application schemas.
FAQ
Frequently asked questions
Are YAML comments preserved?
No preservation guarantee is made. Parsing to JavaScript data and stringifying it can remove comments and other source annotations.
Does YAML Formatter preserve key order?
Output generally follows the parsed object's property order, but exact source ordering and representation are not guaranteed.
Are anchors and aliases supported?
The parser may read supported anchors and aliases, but parse-and-stringify can resolve or rewrite them rather than preserve their original source form.
Can I choose YAML indentation?
No. The current tool uses the YAML library's default stringify formatting.
Does it support multi-document YAML?
No. The current implementation uses a single-document parse operation.
Why did quotes or block strings change?
The formatter serializes parsed values into fresh YAML, so the library may choose a different but equivalent scalar representation.