YAML Input

Formatted Output

Indent:

What is YAML Formatter?

Got messy YAML (YAML Ain't Markup Language) that's impossible to read? This tool fixes that. It takes your YAML and makes it beautiful – proper indentation, line breaks, everything organized. Whether you're working with Docker Compose, Kubernetes configs, CI/CD pipelines, or just trying to understand what your YAML actually says, this makes it readable. Learn more about YAML on Wikipedia.

According to YAML specification, YAML is a human-readable data serialization standard. The formatter parses your YAML and writes it back out with consistent indentation, so the output is always valid YAML with the same keys and values. Two things don't survive that round trip, so know them before you format a file you care about: comments are removed, and anchors and aliases are expanded into full copies. Dates, big integers and multi-document files (---) are kept as they were.

Best part? Everything happens instantly in your browser. No server uploads, no data storage – just paste, format, and copy. Your YAML stays private. To cross-check, you can also run your output through another online YAML formatter.

How to Use the YAML Formatter

Follow these steps to format and beautify your YAML.

Paste, Upload, or Load Sample

Paste minified YAML into the left YAML Input panel, or click Upload to load a .yaml or .yml file. Click Sample to see example telecomm subscriber YAML. Example:

subscriber:
  subscriberId: SUB-1001
  plan: Unlimited 5G
  dataUsage: 45.2
  status: active
  carrier: Verizon

Invalid YAML will show an error. Fix syntax errors first, then format again.

View Formatted Output

The right Formatted Output panel shows the formatted YAML instantly. Use Indent (2 or 4 spaces) and Sort Keys to customize the output.

Copy or Download

Click Copy to copy the formatted YAML to your clipboard, or Download to save as a .yaml file. Use Clear on the input panel to start fresh. All processing runs in your browser.

When You'd Actually Use This

Docker Compose

Format Docker Compose YAML files to understand the structure, debug issues, or improve readability. Works great with docker-compose.yml files.

Kubernetes Configs

Format Kubernetes YAML manifests to review deployments, services, or config maps. Makes it easier to spot errors or understand configurations.

CI/CD Pipelines

Format GitHub Actions, GitLab CI, or other CI/CD YAML configs. Easier to review, debug, or modify pipeline configurations.

Config File Review

Reviewing YAML configuration files? Format them first to see the structure clearly. Makes it easier to spot errors, understand settings, or compare different configurations.

Common Questions

Is my YAML data stored?

No. All formatting happens in your browser using JavaScript. Your YAML never leaves your computer.

What YAML formats are supported?

Any valid YAML: nested mappings, sequences, multi-line strings, and files with several documents separated by ---. Comments are dropped and anchors (&base / *base) are expanded, because the file is re-written from its parsed data. If you need comments kept, format by hand or with an editor plugin that edits the document in place.

Can I format invalid YAML?

No. Formatting starts with a successful parse, so broken YAML gets you the parser's error message, complete with the line and column where it gave up, rather than any output. Correct that spot, or paste the file into the YAML Validator to see the problem, then come back.

What indentation does it use?

Two spaces by default, which is what Kubernetes, Compose and most style guides use. Click 4 next to Indent above the output to switch to four spaces.

How big can my file be?

Since processing happens in your browser, performance depends on your device. Small files format instantly. Very large files (several MB) might take a few seconds, but they'll still work.

Does key sorting affect functionality?

No. Key sorting is purely cosmetic – it only changes the order keys appear, not their values or functionality. Useful for consistent formatting or cleaner diffs.

Other YAML Tools You Might Need

Formatting is just one YAML task. Here are other tools that work well together:

YAML Formatter - Beautify and Format YAML Online