JSON Utility
Free, browser-based tools for working with JSON, YAML, and XML — validate, format, convert, compare, and query, all without an account and without uploading your data anywhere. Everything runs client-side, in your own browser.
Our Tools
Validate and beautify JSON, YAML, or XML with line numbers and clear, actionable error messages.
Convert JSON to XML, YAML, or JSON Schema (and back) in your browser, no uploads required.
Run JSONPath expressions against your JSON and see matching results instantly.
Validate JSON data against any JSON Schema and get clear, actionable error messages.
Validate OpenAI function-calling and Anthropic tool-use schemas, then test sample arguments against them.
Drop multiple JSON files at once and validate every one in your browser, with a pass/fail list.
Compare two JSON documents side by side and see exactly what changed.
Compare two YAML files and spot added, removed, or changed values at a glance.
Compare two XML documents and quickly find structural or value differences.
Why JSON Utility
These are the everyday tools a developer reaches for when debugging an API response, comparing config files, or checking a payload against a schema. No registration, no rate limits, and your data never leaves your device. Read more on our About page, or see how we handle data and cookies in our Privacy Policy.
FAQ
- Is my data uploaded to a server?
No. All tools run locally in your browser; your data isn't sent to any server.
- Can I use the tool offline?
After the page loads once, most browsers will allow basic offline usage because processing is entirely client-side.
- Can I beautify JSON?
Yes - use the Beautify actions in each tool where applicable.
- Do you keep my files?
No. All tools run locally in your browser; data is not uploaded to any server.
- Is there a size limit?
Large inputs are limited by your browser memory; for most cases typical files work fine.
- Is it free?
Yes, All tools are 100% free and no sign-up required.