JSON Ox

The JSON formatter that stays on your machine. Format, validate, and inspect JSON privately — zero data leaves your browser.

Built for the agentic web
Drop .json or
Max 20 MB

Frequently Asked Questions

What is JSON Ox?
JSON Ox is a high-performance JSON formatter built for developers and AI workflows. It formats, minifies, and validates JSON entirely in your browser — and is designed to act as a handover target for AI agents, letting tools like Claude or ChatGPT pass data directly into the formatter via a deep link.
How do you handle my data?
Locally. Your JSON is processed entirely in your browser. We follow high-tier protocols — including a strict Content Security Policy — to ensure a leak-proof environment. You can verify our bench-test results on the Mozilla Observatory.
Pretty Print vs. Minify: Which should I use?
Pretty Print is designed for human consumption, using indentation to make nested objects scannable. Minify is built for production performance — it strips all non-essential whitespace to reduce payload size and improve network transfer speeds.
Does this tool check for errors?
Yes. As you paste or type, JSON Ox instantly validates against the JSON spec. If something is wrong — a missing comma, a trailing bracket, an unquoted key — we highlight the exact line and give you a plain-English hint on how to fix it.
What is 'Copy for AI'? And when should I use it?
Copy for AI wraps your formatted JSON in Markdown code fences (```json). Use it when passing data into an AI assistant. The fencing signals to the model that the content is structured data, not prose — which prevents it from paraphrasing, reformatting, or accidentally altering your schema in its response.
Can AI agents send data directly to JSON Ox?
Yes — this is a core design feature. JSON Ox exposes a deep-link protocol documented in llms.txt, which AI agents can read to understand how to hand off data. For small payloads, an agent can encode JSON into a URL and link the user directly to a pre-loaded formatter. For larger payloads, the protocol defines a clipboard handover path. This makes JSON Ox useful as an inspection layer inside AI-assisted workflows — not just as a standalone tool.
Can it handle large files?
Yes. JSON Ox uses Web Workers and Transferable Objects to process multi-megabyte files without freezing the browser UI. For very large results, the text preview is automatically disabled to preserve memory — Copy and Download remain available instantly.
Why are there indentation options?
To match your project's code style and avoid linter errors when pasting into your editor. 2-space is the JSON default; 4-space suits Python and Java conventions; tab indentation is common in Go projects and some editor configurations.