YAML Formatter

A YAML formatter cleans and indents YAML so keys, lists, and nested objects are easy to read. It catches spacing issues that break parsers and shows structure clearly. Use it for Kubernetes manifests, CI configs, or any YAML file without scrolling through misaligned lines.

1. Paste or drop YAML: Paste a config, manifest, or pipeline file into the input panel — or drag-and-drop a .yaml / .yml file directly. Formatting starts automatically.
2. Adjust options if needed: Change indent size (2, 4, or 8 spaces), line width, key sorting, or string quoting. The output updates live as you change settings.
3. Copy or download: Grab the formatted YAML from the output panel with one click — copy to clipboard or download as a .yaml file.

• Prevent parser errors: Consistent spacing avoids painful indentation bugs that silently break deployments.
• Faster code reviews: Clean layout speeds up reviews and makes diffs easier to read in pull requests.
• Sort keys for cleaner diffs: Alphabetically sorted keys reduce meaningless reordering noise in version control.
• Local privacy: Formatting runs entirely in your browser — secrets, API keys, and env variables never leave your device.

Use case 1: Kubernetes manifests

Format Deployments, Services, ConfigMaps, and Ingress resources to verify selectors, ports, and probes align correctly. Especially helpful when copying YAML from documentation that uses inconsistent indentation.

Use case 2: Docker Compose files

Beautify multi-service compose files to confirm service dependencies, volume mounts, and environment variables nest as intended. Makes it easy to spot missing or extra indentation before running docker compose up.

Use case 3: CI/CD pipelines

Clean up GitHub Actions workflows, GitLab CI files, or CircleCI configs to confirm jobs, steps, and matrix strategies are properly structured. Formatting catches common issues like misaligned run: or env: blocks.

Use case 4: Application configs

Tidy feature flag files, logging configs, or environment-specific settings before committing. Sorting keys alphabetically makes large config files easier to navigate.

Basic example

Input: Inconsistently indented Kubernetes config

apiVersion: v1
kind: ConfigMap
metadata:
    name: app-config
data:
      key: value
      database_url: postgres://localhost:5432/app

Output: Clean 2-space indentation

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  key: value
  database_url: postgres://localhost:5432/app

Advanced example

Input: Messy Docker Compose with mixed indentation Output: Consistent formatting with all services, volumes, and networks properly aligned under their parent keys.

Tab characters

YAML requires spaces — tabs are not allowed. If you see a parser error mentioning tabs, replace them with spaces (most editors have a "Convert Indentation to Spaces" command).

Misaligned list items

List dashes (-) must align with their parent key's indentation level. The formatter will flag this with a parse error showing the exact line number.

Duplicate keys

YAML allows duplicate keys but only the last value is kept. The formatter will parse successfully but you may lose data. Check for warnings about duplicate keys in your editor.

• Stick to 2-space indent for most YAML — it keeps lines short and matches Kubernetes/Docker conventions.
• Enable sort keys for config files to get cleaner git diffs and easier alphabetical lookups.
• Validate after formatting with your CLI tool (kubectl apply --dry-run, docker compose config, ansible-lint).
• Pair with the JSON to YAML converter when migrating configs between formats.
• Use the YAML to JSON converter to verify complex YAML parses as expected.

• Convert YAML to JSON using the YAML to JSON converter.
• Convert JSON to YAML using the JSON to YAML converter.
• Clean JSON files using the JSON formatter.
• Format XML files with the XML formatter.
• Format GraphQL schemas with the GraphQL formatter.

All formatting happens locally in your browser using JavaScript. No YAML content is uploaded, stored, or transmitted to any server. This makes it safe to format configs containing database credentials, API keys, cloud secrets, and other sensitive values.