JSON Schema Generator
Infer a complete JSON Schema from sample data.
Runs 100% in your browser — nothing is ever uploaded.
What is JSON Schema Generator?
Generate a JSON Schema (draft 2020-12) from any sample JSON document instantly, with types and required fields. 100% client-side. Paste your content, get an instant result, and copy or download the output with a single click. It's completely free, works in any modern browser and requires no sign-up — everything runs locally on your device, so your data never leaves your computer.
How to use JSON Schema Generator
- Open JSON Schema Generator — it loads instantly and needs no sign-up.
- Paste or type your input into the editor (or press Sample to try an example).
- Adjust the available options if needed and press the action button.
- Copy the result with one click or download it as a file.
Frequently asked questions
Is JSON Schema Generator really free?
Yes — JSON Schema Generator is 100% free with no limits, no watermarks and no registration. You can use it as often as you like, on as many files or inputs as you need.
Is my data safe when I use JSON Schema Generator?
Absolutely. JSON Schema Generator runs entirely in your browser using JavaScript — your input is processed on your own device and is never uploaded to any server.
Does JSON Schema Generator work on mobile devices?
Yes. JSON Schema Generator works in any modern browser on desktop, tablet and mobile (Chrome, Firefox, Safari, Edge) — there is no app to install.
Is it safe to generate passwords in a browser?
Yes — we use the Web Crypto API (crypto.getRandomValues), the same cryptographically secure randomness source used by password managers. Generation happens on your device and nothing is transmitted or stored.
Do you see the JWT tokens I decode?
No. Decoding is pure client-side Base64 parsing — the token never leaves your browser. Still, avoid pasting production secrets anywhere as a general habit.
Are the UUIDs really unique?
UUID v4 has 122 random bits — the collision probability is so small it is negligible for any real-world system. We use the native crypto.randomUUID() implementation.