JSON Formatter & Viewer
Format, validate, and explore JSON with syntax highlighting, collapsible tree, and interactive grid.
"name""hello"42 / 3.14true / falsenullAbout the JSON Formatter & Viewer
JSON Formatter lets you instantly beautify, validate, and minify JSON data right in your browser. Paste a raw or compact JSON string and get clean, indented output in one click — no sign-up, no installs, no waiting. Whether you're inspecting an API response or cleaning up config files, the formatter flags syntax errors before they reach your code.
Minification strips all unnecessary whitespace from your JSON, shrinking payload size for faster API calls and network transfers. The validator catches missing brackets, trailing commas, and unquoted keys, giving you a clear error message so you can fix issues fast. All processing happens client-side, so your data never leaves your machine.
How to use the JSON Formatter & Viewer
- Paste your raw or minified JSON into the input box on the left.
- Click 'Format' to beautify with 2-space or 4-space indentation, or click 'Minify' to compress it.
- Review any validation errors highlighted in red below the editor.
- Click 'Copy' to copy the formatted output to your clipboard.
- Use 'Clear' to reset both panes and start fresh with new JSON.
Key features
- Instant syntax validation with line-specific error messages
- Beautify with configurable indentation (2 or 4 spaces)
- One-click minification to reduce JSON payload size
- Clipboard copy button for frictionless workflow
- Runs entirely in the browser — no data is sent to any server
- Handles large JSON documents without size limits imposed by a backend
Frequently asked questions
Why does my JSON show a validation error?
Common causes include trailing commas after the last item in an array or object, single-quoted strings instead of double-quoted ones, or missing closing brackets. The formatter highlights the exact line where the error occurs so you can fix it quickly.
What is the difference between formatting and minifying JSON?
Formatting adds indentation and line breaks to make JSON human-readable. Minifying removes all whitespace to produce the smallest possible string, which is better for network transmission and storage but harder to read manually.
Is there a size limit on the JSON I can paste?
Because processing happens entirely in your browser, the only limit is your device's available memory. Most everyday JSON files and API responses — even large ones with thousands of records — format without any issue.
Can I use this to validate JSON before sending it to an API?
Yes. Paste your JSON, click Format, and any syntax problems will be flagged immediately. Fix the highlighted errors, then copy the clean output directly into your request body or code.
Does the formatter support JSON5 or comments in JSON?
The formatter strictly follows the JSON specification (RFC 8259), which does not allow comments or unquoted keys. For JSON5 or JSONC files, you would need to strip comments before pasting.
All JSON processing runs locally in your browser — your data is never uploaded to any server.