About Prettify YAML
YAML decides structure by indentation, which is great until one space goes missing and the whole file suddenly means something different. This tool reformats your YAML cleanly and catches the errors that would otherwise surface mid-deploy.
You'll appreciate it most with the YAML that runs infrastructure:
docker-compose.yml files, GitHub Actions and GitLab CI
pipelines, Ansible playbooks, Kubernetes manifests. A stray tab or a
misaligned key breaks all of them, and it's rarely obvious where.
Processing happens entirely in the browser, so it's safe to run configs that contain secrets through it. Pick 2 or 4 spaces for the output, then copy or download.
How to pretty print YAML
Paste YAML into the input and choose 2 or 4 spaces for indentation. Live mode formats as you type; turn it off and click Format YAML to check syntax explicitly. Copy or download the formatted output.
For example, the compact YAML below can be expanded into an indented mapping:
Input:
app: {name: demo, port: 8080}
Formatted with 2 spaces:
app:
name: demo
port: 8080The formatter parses and rewrites YAML, so comments and original styling are not preserved. Syntax checking does not validate application-specific settings in Docker Compose or Kubernetes configurations.
Frequently Asked Questions
What is a YAML formatter used for?
A YAML formatter standardizes the layout of YAML files with consistent indentation so they are readable and valid. It is commonly used on configuration files, docker-compose.yml files, CI/CD pipelines and Kubernetes manifests.
Can it validate Kubernetes manifests?
This tool validates YAML syntax and structure, which catches the most common Kubernetes manifest errors such as broken indentation, duplicate keys and malformed lists. For full schema validation against Kubernetes API objects, pair it with kubectl dry-run.
Why is YAML indentation so strict?
YAML uses indentation (spaces, not tabs) to define structure — unlike JSON, there are no braces. One wrong space changes the meaning of the whole document, which is why a formatter that normalizes indentation is so valuable.
Is my YAML private?
Yes. Formatting and validation run entirely in your browser. Your YAML never leaves your device, so it is safe to format configs containing secrets or internal infrastructure details.