YAML Formatter
Format and prettify YAML documents instantly in your browser.
This tool runs entirely in your browser. Your files are never uploaded to a server.
name: Ada Lovelace born: 1815 knownFor: - mathematics - computing
What this tool does
Parses one YAML document and serializes the resulting data again with consistent two-space indentation. It provides a normalized, readable view while reporting syntax errors instead of returning partial output.
How to use it
Paste a complete YAML document into the input box. Review the formatted result, correct any parser error shown below the editor, and copy the output only after confirming that its represented data still matches your intent.
Worked example
The input `name: Ada Lovelace` followed by `skills: [math, computing]` becomes a mapping whose skills value is displayed as a two-item indented sequence. The data is unchanged even though its presentation differs.
Formatting method
The tool uses js-yaml to load the text as a JavaScript value and dump that value with an indentation width of two and without automatic line wrapping. Blank input produces no output, and only one YAML document is accepted.
What normalization changes
Re-serialization can change quoting, flow collections, scalar spelling, anchors, key presentation, and other stylistic details. Comments are not data nodes and are not preserved, so compare the result carefully before replacing a hand-maintained file.
Validation limits
Successful parsing checks YAML syntax, not an application's schema or business rules. It cannot confirm that Kubernetes, Docker Compose, CI, or another consumer recognizes the keys, types, versions, or values in the document.
Privacy and verification
Formatting runs locally in the browser and Quiklio does not upload the pasted YAML. Secrets can still be exposed through the clipboard, extensions, screenshots, or the device, so use sanitized samples and validate important output with its target application.
Frequently Asked Questions
- What does this tool do?
- It parses your YAML document and re-serializes it with consistent, properly nested indentation, making it easier to read and spot mistakes.
- Does it catch YAML syntax errors?
- Yes — if your YAML can't be parsed, the tool shows an error pointing to the problem so you can fix it before using the file.
- Is my data safe?
- Yes. Formatting happens entirely in your browser using JavaScript — your YAML is never sent to a server, so it stays private, and the tool is completely free with no sign-up.