JSON Formatter – Free Online Tool
Free online JSON formatter, validator, and beautifier with tree view, auto-repair, TypeScript generator, and statistics dashboard. 100% client-side.
The Most Powerful Free JSON Formatter Online
Our JSON Formatter goes far beyond simple beautification. It combines formatting, validation, auto-repair, tree exploration, TypeScript generation, and statistical analysis in a single tool — eliminating the need to juggle multiple tabs. Everything runs 100% in your browser using client-side JavaScript, so your API keys, tokens, and sensitive data never leave your device.
Smart Auto-Repair for Broken JSON
Paste broken JSON and watch it get fixed automatically. Our repair engine handles trailing commas, single quotes instead of double quotes, unquoted keys, JavaScript comments, undefined values, and NaN — common issues when copying from code editors, APIs, or AI chat outputs. The validation indicator shows whether the JSON was valid or auto-repaired.
Why Developers Choose Our JSON Formatter
Unlike jsonformatter.org or jsonlint.com, we never send your data to a server. Plus we offer features no competitor combines in one tool: an interactive tree view with click-to-copy JSONPath, auto-generated TypeScript interfaces, a statistics dashboard showing key counts and type distribution, and smart auto-repair for broken JSON from AI outputs and messy APIs.
Who Benefits from This JSON Tool
Frontend developers debugging API responses, backend engineers validating webhook payloads, DevOps teams working with configuration files, data scientists exploring JSON datasets, QA testers validating test fixtures, and anyone who works with JSON regularly. Our tool handles files up to 10MB with instant formatting and responsive tree rendering.
How to Use JSON Formatter
- 1
Paste your JSON into the editor or upload a .json file — it formats instantly on paste
- 2
Use the toolbar to minify, sort keys, repair, or switch to Tree View for visual exploration
- 3
Copy the formatted output, download as a file, or generate TypeScript interfaces with one click. Keyboard shortcuts: Ctrl+Enter to format, Ctrl+Shift+M to minify
Frequently Asked Questions
Everything you need to know about the JSON Formatter.
Is this JSON formatter really free and unlimited?
Yes, completely free with no limits. Format, validate, and explore as much JSON as you want. Everything runs in your browser — there are no server costs, no accounts, no daily limits, and no ads blocking your workflow.
Can this tool fix broken or invalid JSON?
Yes! Our auto-repair engine handles the most common JSON issues: trailing commas, single quotes, unquoted keys, JavaScript-style comments, undefined/NaN values, and other syntax errors commonly found in code editor output, AI-generated JSON, and API responses.
Is my JSON data safe and private?
Absolutely. All processing happens locally in your browser using client-side JavaScript. Your JSON data — including API keys, tokens, database dumps, and configuration files — is never sent to any server. This makes our tool safe for sensitive production data.
What is the Tree View and how does it work?
The Tree View renders your JSON as an interactive, collapsible tree with color-coded type indicators (strings, numbers, booleans, arrays, objects, nulls). You can expand/collapse nodes, search across keys and values, and double-click any node to copy its JSONPath — perfect for navigating large, deeply nested JSON structures.
How does the TypeScript generator work?
When you paste valid JSON, our tool automatically generates TypeScript interfaces that match your data structure. It handles nested objects, arrays of objects (using the first element as the type template), primitive types, and nullable values. One click copies the generated types to your clipboard.
What keyboard shortcuts are available?
Ctrl+Enter (or Cmd+Enter on Mac) instantly formats your JSON. Ctrl+Shift+M minifies it to a single line. The Monaco editor also supports standard shortcuts like Ctrl+F for find, Ctrl+Z for undo, and Ctrl+D to duplicate a line.