YAML Formatter

About this tool

YAML files accumulate inconsistent indentation faster than most formats, because the whitespace is both the syntax and the styling. A Helm chart or a CI config that several people have edited will typically have two-space blocks next to four-space blocks, and lists indented under their key in one place and level with it in another. All of it parses; none of it reads well.

Formatting here goes through the document tree rather than through a plain value, which is what makes it safe to run on a real config file: comments survive. A round trip that parsed to an object and re-emitted it would drop every comment in the file, and in a deployment manifest the comments are frequently the only documentation there is.

Multi-document streams are handled as streams. Every document between separators is formatted and all of them come back, which is the behaviour a Kubernetes manifest needs.

How to use this tool

1. 1

   Paste YAML, or upload a .yaml or .yml file.

2. 2

   Set the indent width and, if you want lines wrapped, a wrap column.

3. 3

   Turn on "Sort keys alphabetically" if you want a stable order for diffing.

4. 4

   Press Format, then copy or download the result.

Key features

• Comments preserved, including trailing comments on a line
• Every document in a multi-document stream formatted and returned
• Configurable indent width and line-wrap column
• Optional recursive alphabetical key sorting, leaving list order untouched
• Anchors and aliases left intact rather than expanded
• Indentation and tab errors reported with a line and a column

Example

# billing service
service:   billing-api
image:
      repository: registry.example.test/billing
      tag: "2026.04.1"   # pinned

# billing service
service: billing-api
image:
  repository: registry.example.test/billing
  tag: "2026.04.1" # pinned

Good to know

Frequently asked questions