YAML Formatter

• 100% Free

  Core tools stay free with no paywall to unlock basics.

• No Registration Required

  Open a tool and start immediately - no account needed.

• Privacy First

  We avoid unnecessary collection and keep processing local when possible.

• Browser Processing

  Most tools run in your browser so your input never needs a server round-trip.

• Fast & Secure

  HTTPS everywhere with instant, client-side results for everyday tasks.

• Mobile Friendly

  Layouts and controls are built for phones, tablets, and desktops.

• Updated Regularly

  Tools and content are improved continuously as the platform grows.

Key Features

• Consistent Two-Space Indentation

  Detects the smallest indentation used in your document and renormalizes every nested key and list item to a clean two-space step.

• Tabs & Mixed-Indent Detection

  Flags files that mix tabs and spaces, or that use inconsistent indentation jumps, before they cause a confusing parser error elsewhere.

• Comment-Preserving Format

  Keeps # comments attached to their original line so annotated Kubernetes manifests and CI configs stay documented after reformatting.

• Advanced-Syntax Guardrails

  Detects anchors, aliases, tags, flow collections, and block scalars and tells you plainly when a document needs a full YAML parser instead.

How to Use

1. 1

   Paste your YAML

   Copy config from a Docker Compose file, Kubernetes manifest, GitHub Actions workflow, or application settings file.

2. 2

   Choose Format or Minify

   Format normalizes indentation to two spaces per level; Minify joins simple key-value pairs and list items onto a single line.

3. 3

   Resolve any reported issue

   Tab characters, mixed indentation, or advanced syntax like anchors and flow collections are called out with a specific message.

4. 4

   Copy or download the result

   Export the cleaned-up YAML to your clipboard or save it as a .yaml file for your repository.

Use Cases

• Cleaning up copy-pasted Kubernetes manifests

  Manifests copied between documentation, Slack, and a terminal often pick up inconsistent indentation - normalize it before applying with kubectl.

• Reviewing CI/CD workflow files

  Format GitHub Actions, GitLab CI, or CircleCI YAML pulled from a template so steps and jobs are easy to read before you edit them.

• Auditing Docker Compose services

  Check that nested service, network, and volume definitions line up correctly after merging changes from multiple contributors.

• Catching tab characters before deployment

  Some editors silently insert tabs into YAML; catch the mixed-indentation error here instead of during a failed deploy pipeline run.

Examples

app:
    name: toolmint
    env: production

app:
  name: toolmint
  env: production

# service config
name: api
port: 8080
tags:
  - prod
  - web

name: api port: 8080 tags: - prod - web

Benefits

• ✓Normalizes inconsistent or copy-pasted indentation to a clean two-space standard automatically
• ✓Catches tab characters and mixed indentation before they cause a cryptic parser failure
• ✓Keeps # comments attached to their line so documented configs stay documented
• ✓Warns clearly when a document uses anchors, aliases, or flow syntax it does not support
• ✓Runs entirely client-side, so Kubernetes secrets and CI configs never leave your browser

Best Practices

• Run Format immediately after pasting YAML from chat, docs, or email - those sources often corrupt indentation.
• Treat a tab-character warning as a hard blocker; most YAML parsers reject tabs in indentation outright.
• Keep secrets out of pasted YAML even though nothing leaves your browser - screen-recording tools may still capture it.
• For documents using anchors, aliases, or multi-line block scalars, format them in an editor with full YAML-aware tooling instead.

Common Mistakes

• Mixing tabs and spaces in the same file, which the YAML specification forbids and this tool explicitly rejects.
• Assuming this formatter supports the full YAML 1.2 spec - anchors, aliases, tags, and flow collections need a complete parser.
• Minifying deeply nested configuration and expecting it to remain valid YAML - minify is meant for quick inspection, not redeployment.

Privacy Notice

All indentation analysis, formatting, and minifying happens locally in your browser. Configuration files, including anything containing environment variables or connection strings, are never uploaded to ToolMint servers.

About This Tool

Frequently Asked Questions

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