YAML formatter & validator

Parse YAML locally in your browser: pretty-print with consistent indentation, live validation, and clearer errors with line/column hints. Export JSON when you need it. Your content stays on your device.

Report

Input YAML

0 Invalid or not yet checked

Output

0 Indent 2 spaces

Step 1

Paste YAML on the left or use “Load file” to open a .yaml / .yml file.

Step 2

Choose indent 2 or 4 to reformat. Use “To JSON” when you need JSON for an API or tests.

Step 3

See the result on the right; copy or download. The input panel shows whether the document is valid.

When should I use this tool?

Whenever you want readable indentation for Kubernetes, Helm, Docker Compose, GitHub Actions, or similar configs—or before diffing two files. It is also handy to quickly produce JSON for tools that only accept JSON.

Why do comments disappear after formatting?

The page parses YAML into a data structure and serializes it again, so comments and the original layout are not preserved. That is normal for parse-and-dump formatters. Keep comments only by editing in an editor that preserves them.

What do the line and column in errors mean?

They come from the parser’s mark and are a hint (usually 1-based) pointing near the problem—useful for missing colons, bad indentation, or multiline string issues.

Is my data sent to your server?

No. Parsing and formatting run entirely in your browser; we do not store or analyze your input on our servers.

How is this different from the data format converter?

This tool focuses on YAML readability, validation, and a quick JSON view. For multi-way conversion between YAML, JSON, XML, and TOML, use the site’s data format converter.

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YAML formatter & validator

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