Is the YAML Formatter free?

Yes — the YAML Formatter is completely free, with no account, subscription, signup, or usage limits.

Is my data uploaded or stored?

No. The YAML Formatter processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.

Does the YAML Formatter work offline?

Yes. Once the page has finished loading, the YAML Formatter works without an internet connection.

Which browsers does the YAML Formatter work in?

The YAML Formatter works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.

Why does my YAML fail when I use tabs?

YAML strictly prohibits tab characters for indentation — only spaces are allowed. This is the most common cause of YAML parse errors. Replace all tabs with spaces (2 or 4) and the error will resolve. Most code editors have a "Convert Indentation to Spaces" option in their settings.

Can I use this to validate Kubernetes or Docker Compose files?

Yes — this tool validates standard YAML syntax and will catch indentation errors, duplicate keys, and invalid characters. Note that it does not validate Kubernetes schema rules (invalid field names, wrong value types per spec) — only the underlying YAML structure. Use kubectl --dry-run for full schema validation.

YAML Formatter

Format and validate YAML files with clear syntax error reporting.

Input

Formatted Output

Output appears here…

Free browser-based tool · Runs 100% on your device · Last updated July 7, 2026

What is the YAML Formatter?

The free YAML Formatter validates and beautifies YAML files instantly in your browser. Paste your YAML into the Input textarea and the tool checks it for syntax errors using a full YAML parser — then re-formats it with consistent 2-space indentation and clean structure in the Output panel. Whether you're working with Docker Compose files, Kubernetes manifests, GitHub Actions workflows, or Ansible playbooks, this free tool catches errors before they break your build.

→ Validate and format Docker Compose and Kubernetes YAML manifests
→ Check GitHub Actions, GitLab CI, or Bitbucket Pipelines workflow files for errors
→ Clean up YAML configuration files for Ansible, Helm, or Terraform
→ Fix indentation errors in YAML that cause silent failures at runtime
→ Inspect and reformat OpenAPI (Swagger) specs written in YAML format

How to Use the YAML Formatter

1 Paste your YAML content into the Input textarea.
2 Switch between Format mode (re-indent and normalise spacing) and Validate mode (check for errors without changing the content) using the toggle.
3 If there are syntax errors, a red error message shows the line number and a description of the problem.
4 If valid, the formatted output appears in the Output panel with consistent 2-space indentation.
5 Click Copy to copy the cleaned YAML to your clipboard.

Key Features

✅
Full YAML parsing

Uses a complete YAML parser — catches indentation errors, tab characters, duplicate keys, and invalid values.
🖊️
Consistent formatting

Re-indents with 2 spaces and normalises structure for readability.
⚡
Instant feedback

Errors are shown immediately as you type or paste.
🔒
Private processing

Your YAML never leaves your browser — safe for API keys, secrets, and private config files.
🆓
No upload required

Paste directly — no file upload, no size limits, no account needed.

Example Usage

Example Input

name: my-app
version: "1.0"
services:
  - web
  - db

Example Output

name: my-app
version: "1.0"
services:
  - web
  - db

Frequently Asked Questions about the YAML Formatter

What is the YAML Formatter?: The YAML Formatter is a free online tool that lets you format and validate YAML files with clear syntax error reporting. It runs entirely in your browser, so there is nothing to install and nothing is uploaded to a server.
Is the YAML Formatter free?: Yes — the YAML Formatter is completely free, with no account, subscription, signup, or usage limits.
Is my data uploaded or stored?: No. The YAML Formatter processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.
Does the YAML Formatter work offline?: Yes. Once the page has finished loading, the YAML Formatter works without an internet connection.
Which browsers does the YAML Formatter work in?: The YAML Formatter works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.
Why does my YAML fail when I use tabs?: YAML strictly prohibits tab characters for indentation — only spaces are allowed. This is the most common cause of YAML parse errors. Replace all tabs with spaces (2 or 4) and the error will resolve. Most code editors have a "Convert Indentation to Spaces" option in their settings.
Can I use this to validate Kubernetes or Docker Compose files?: Yes — this tool validates standard YAML syntax and will catch indentation errors, duplicate keys, and invalid characters. Note that it does not validate Kubernetes schema rules (invalid field names, wrong value types per spec) — only the underlying YAML structure. Use kubectl --dry-run for full schema validation.