JSON Formatter
Format, validate, beautify, minify and analyze JSON in an IDE-style editor with precise error messages, an interactive tree explorer, diff comparison and TXT/JSON/CSV export. Free and private.
What is the JSON Formatter?
A JSON Formatter is a developer tool that turns messy or minified JSON into clean, readable, validated data. Toollyz JSON Formatter is a full JSON workspace: an IDE-style editor with syntax highlighting and line numbers, real-time validation that pinpoints the exact line, column and reason for every error (with fix hints), one-click beautify and minify with 2-space, 4-space or tab indentation, key sorting, and escape/unescape utilities. An interactive tree explorer lets you expand, collapse, search and copy the path of any node, a statistics dashboard summarizes objects, arrays, keys, depth and size, and a diff view compares two JSON documents and highlights every added, removed and changed value. Import files by drag-and-drop and export to JSON, minified JSON or CSV — all running privately in your browser, so your data is never uploaded.
How to use it
- Paste, type or drop a JSON file into the editor — it validates as you type.
- Click Format to beautify (or Minify to compress), and choose your indentation.
- Explore the structure in the tree view, check the statistics, or search for any key or value.
- Compare against a second JSON in the Diff tab, then copy or export to JSON, minified or CSV.
Benefits
- Real-time validation with the exact line, column, message and a fix hint for every error.
- IDE-style editor with JSON syntax highlighting, line numbers and code-style typography.
- One-click beautify and minify with 2-space, 4-space or tab indentation.
- Interactive tree explorer: expand/collapse, search keys and values, and copy any JSON path.
- Statistics dashboard — objects, arrays, keys, depth, node count, size and a health score.
- JSON diff to compare two documents with added, removed and changed highlights.
- Sort keys, escape/unescape, undo/redo and saved-session history.
- Import by drag-and-drop and export to JSON, minified JSON or CSV — 100% private, no upload.
Frequently asked questions
What is a JSON formatter?
A JSON formatter takes raw JSON and reformats it into a clean, indented, human-readable structure. Toollyz JSON Formatter also validates the data, visualizes it as a tree, reports errors precisely and lets you minify, sort, diff and export it.
How does JSON validation work?
As you type, the tool parses your JSON with a strict parser. If something is wrong — a missing comma, an unclosed bracket, a trailing comma or invalid quotes — it shows the exact line and column, a clear message and a hint on how to fix it, with a Jump button to take you there.
Can I beautify JSON instantly?
Yes. Click Format (or press Ctrl/⌘ S) to pretty-print your JSON with your chosen indentation — 2 spaces, 4 spaces or tabs. Formatting happens entirely in your browser, so it's instant even for large documents.
Can I minify JSON?
Yes. The Minify button strips all whitespace to produce the smallest valid JSON for production or transport. You can also download the minified version directly.
Can I upload JSON files?
Yes. Drag and drop a .json or .txt file onto the editor, or use the Import button. The contents load straight into the editor for formatting and inspection.
Does this support large JSON files?
Yes. Parsing, formatting and statistics run efficiently in your browser, and the tree explorer loads nodes on demand so you can navigate large, deeply nested documents smoothly.
Can I compare two JSON documents?
Yes. Open the Diff tab and paste a second JSON document. The tool highlights every added, removed and changed value with its path, so you can spot API or data differences at a glance.
Is my JSON stored online?
No. All formatting, validation and analysis happen entirely in your browser — your JSON is never uploaded to any server. Saved sessions are kept only in your device's local storage.
Does it work on mobile?
Yes. The editor, validation, tree explorer, statistics and diff are fully responsive and touch-friendly, so you can format and inspect JSON on any device.
Is this JSON formatter free?
Completely free with no signup and no limits. Formatting, validation, the tree viewer, diff, statistics and exports are all available to everyone, privately in your browser.