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Validator

Basic syntax sanity check for JSON (full parse), XML (root-element check), and YAML (real js-yaml parse) — JavaScript not included. Code never leaves your device. Code never leaves your device — formatting and validation run locally in your browser.

100% Local Browser Native

How to Use the Validator

1. Paste the code block

The snippet exactly as written — indentation and brackets intact.

2. Read pass or the error text

JSON, XML, and YAML all parse for real; YAML errors name the bad line. Errors carry no line numbers beyond that.

3. Fix top-down

Repair the first error first — later ones are often its cascade.

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Frequently Asked Questions

Which languages validate here?

JSON (real parse), XML (root-element presence only), and YAML (real js-yaml parse — bad indentation and tabs fail). No JavaScript or grammar-aware parsing.

Line numbers?

None — errors name the format and message only. Fix from the top of the snippet.

Does it auto-fix issues?

No — validation reports problems; deliberate edits stay yours to make.

Is my code uploaded anywhere when using Validator?

No — validation runs locally in your browser, free with no signup.

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Last updated October 2026