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YAML Validator

Free online YAML validator to check the correctness of your YAML data.


What is a YAML validator?

A YAML validator is a tool that allows you to validate YAML files for syntax errors in a simple interface and ensure your YAML data follows the YAML specification. It verifies correct indentation, use of colons, dashes, and brackets, and ensures your YAML document meets predefined schemas.


YAML stands for "YAML Ain't Markup Language." This recursive acronym emphasizes that YAML is designed to be a human-readable data serialization standard, distinct from traditional markup languages like XML.

Initially, YAML stood for "Yet Another Markup Language," but the name was changed to highlight its purpose as a data serialization format rather than a markup language.

To check if your data is in the correct format, paste your YAML file in the input box and click "Validate." Our tool will provide you with the result below the input box.

If your YAML data contains structure or syntax errors, our tool will provide an output with information about the column and row in which the error occurred, along with simplified error details.

Yes, our validator supports YAML 1.1, YAML 1.2, and all common data schemas.

Currently, the pasted YAML files do not have a set size limit.

Our tool allows one YAML file to be validated at a time. Consider using command-line tools or integrating validation into your CI/CD pipeline for bulk validation.

Our YAML validation is based on the npm yaml library.

This tool is designed for use in online browsers. For offline validation, we recommend using command-line tools like yamllint. Follow this guide to install yamllint for your operating system.

A YAML validator checks for syntax correctness and schema conformance, ensuring the file is properly formatted and error-free.

A YAML linter goes further by enforcing style guidelines and best practices, ensuring consistent indentation, proper alignment, and formatting.

Validators check correctness, while linters ensure both correctness and maintainability.

JSON and YAML are both data serialization formats.

A JSON file has a strict syntax with braces and brackets, ideal for web applications and data interchange.

YAML uses indentation and supports comments, making it more readable and often used for configuration files.

JSON is simpler and faster to parse, while YAML is more flexible and easier to read.

You can convert most documents between both these file formats.