Paste JSON, drop a file, or
JSON Formatter & Beautifier
Free online JSON Formatter & Beautifier — format, prettify, validate, minify, view and repair JSON. Fast, private and 100% in your browser.
Features
Built for developers who ship
A premium JSON toolkit with the polish of an IDE and the speed of a static tool.
Beautify & Minify
Pretty-print JSON with 2, 4, or tab indentation, or collapse it down to a single line for transport.
100% Private
Every operation runs locally in your browser. No uploads, no accounts, no telemetry on your data.
Auto JSON Repair
Fix trailing commas, single quotes, unquoted keys, and JavaScript-style comments in a single click.
Interactive tree view
Explore nested structures, search keys and values, and copy JSON paths with one click.
Real-time validation
Get precise line and column diagnostics as you type, powered by the native JSON parser.
Blazing fast
Monaco editor with syntax highlighting, folding, and minimap — handles multi-megabyte payloads.
Keyboard-first
Ctrl/Cmd shortcuts for beautify, minify, copy, and download. Full keyboard navigation everywhere.
Import & Export
Drag-and-drop files, paste from clipboard, download the result, or copy to clipboard instantly.
Sort & clean
Alphabetize keys, remove null values, strip empty objects — perfect for diffs and API contracts.
Learn JSON
The friendly guide to JSON
Why every developer needs a fast, private way to inspect the data that powers their apps.
What is JSON?
JSON — JavaScript Object Notation — is a lightweight, text-based data format used to exchange structured data between systems. Despite its name, it is language-independent and supported by every major programming language.
It was designed to be easy for humans to read and trivial for machines to parse. It maps onto the primitive types most languages already have — strings, numbers, booleans, null, arrays and objects — which is why it eclipsed XML as the default wire format for REST and GraphQL APIs.
{
"name": "JSON Formatter",
"version": "3.0",
"features": ["beautify", "validate", "tree"],
"openSource": true,
"permissions": ["read", "write"]
}Why format JSON?
Parsers don't care about whitespace, but developers do. Consistent indentation, key ordering and line breaks make code reviews faster and diffs meaningful.
A minified payload saves 20–40% of bytes on the wire, and combined with gzip the savings are even larger. Keep the pretty-printed copy in your repo, your logs and your code reviews — the extra whitespace is what makes the file useful to humans.
- Spot bugs faster — indentation exposes missing brackets and misplaced commas at a glance.
- Cleaner diffs — sorted keys keep git blame stable and reduce merge conflicts.
- Better logs — pretty-printed error payloads are actually readable in production.
- Documentation — formatted examples in READMEs and API references convert.
Where developers use JSON
Almost every REST API, mobile app backend and configuration file today speaks JSON.
APIs & webhooks
Requests, responses, event payloads — JSON is the default wire format for HTTP APIs and message queues alike.
Configuration
tsconfig, package.json, VS Code settings and thousands of other tools ship JSON-based config.
Data pipelines
Log shipping, analytics events and streaming systems commonly emit newline-delimited JSON.
JSON vs XML
Choose JSON when…
- • Building a REST or GraphQL API for JavaScript / mobile clients
- • Payload size and parse speed matter
- • Human-readable diffs are a priority
Consider XML when…
- • You need namespaces, mixed content, or XSLT transforms
- • You're integrating with SOAP or legacy enterprise services
- • The document is human-authored (XHTML, DocBook, SVG)
JSON formatting best practices
- 1Pick one naming convention — camelCase or snake_case — and use it everywhere.
- 2Prefer null over missing keys so consumers can rely on the shape.
- 3Use ISO 8601 for dates: 2026-07-01T12:34:56Z, never Unix epochs on the wire.
- 4Version at the URL or Accept header, never in the payload.
- 5Wrap collections in a container ({"data": [...], "next_cursor": "..."}) for future-proof pagination.
- 6Keep payloads flat when nesting adds no semantic value.
JSON security tips
JSON is inert — but how you parse and render it matters.
How it works
Three steps to clean JSON
From messy payload to formatted, validated and exportable JSON in seconds.
- 1
Paste or upload
Paste JSON in the editor, drop a file, or load the sample document.
- 2
Format instantly
Beautify, minify, sort, or repair — everything runs locally in milliseconds.
- 3
Inspect and export
Switch to tree view, copy results, or download a clean .json file.
Code examples
Format JSON from your code
Prefer doing it programmatically? Here are quick one-liners for the most popular languages.
Use json.dumps() with indent parameter to pretty-print JSON in Python.
import json
data = {"name": "JSON Formatter", "version": "3.0"}
print(json.dumps(data, indent=2))Use JSON.stringify() with null and indent to format JSON in JavaScript.
const data = { name: "JSON Formatter", version: "3.0" };
console.log(JSON.stringify(data, null, 2));FAQ
Frequently asked questions
Everything developers ask about formatting, validating, and repairing JSON.
Blog
Developer articles
Deep-dive guides on JSON, APIs, and data tooling.
Guides
Understanding JSON objects, arrays and nested data
The two containers JSON gives you — objects and arrays — combine into every real-world payload. Here's how to model them well.
ReadAPI Guides
How APIs use JSON for data exchange
From REST payloads to GraphQL responses and webhooks, JSON is the lingua franca of modern APIs. Here's how it works in practice.
ReadBest Practices
JSON minification: benefits, drawbacks and use cases
Minifying JSON strips every optional byte. Here's when the savings matter, when they don't, and how to do it without breaking anything.
ReadGet new developer tools first
Occasional updates about new tools, features, and best practices. No spam, unsubscribe anytime.