JSON Formatter
FormattersInstantly format, validate and explore JSON with syntax highlighting, collapsible tree view, and interactive D3 graph. Export as SVG or PNG. 100% browser-based.
About JSON Formatter
The JSON Formatter is a production-grade, browser-based tool that instantly beautifies raw or minified JSON into clean, human-readable output. Powered by the native JSON.parse + JSON.stringify pipeline inside a dedicated Web Worker, formatting is near-instantaneous even on large payloads — and your data never leaves the browser. Beyond simple indentation, the tool provides an interactive Tree View and a card-based Graph View to explore complex nested structures visually, with SVG and PNG export built in.
Features
- ✓Instant beautification via native JSON.parse + JSON.stringify — near-zero latency
- ✓Configurable indentation: 2 spaces, 4 spaces, or tab
- ✓Built-in validation with clear, line-precise error messages on invalid JSON
- ✓Interactive Tree View — collapse and expand nested objects and arrays
- ✓Interactive Graph View — visualise data relationships as a card-based hierarchical node graph
- ✓Export graph as SVG (vector, lossless) or PNG (raster, high-resolution)
- ✓Web Worker execution — all processing runs off the main thread, UI stays responsive
- ✓Syntax-highlighted Monaco-based editor for both input and formatted output
- ✓One-click clipboard copy of formatted output
- ✓Real-time byte-savings stats (input vs output character count)
- ✓Language picker — instantly pivot to 20+ other formatters from the same interface
- ✓Load example JSON with one click; clear input and output independently
- ✓Mobile-responsive layout with a dedicated Format button for small screens
- ✓100% client-side — your data never leaves the browser at any point
Common Use Cases
- Debugging minified API responses by expanding them into readable, indented JSON
- Reviewing JSON configuration files before committing them to source control
- Preparing and validating JSON payloads for Postman, Insomnia, or curl test suites
- Exploring deeply nested API responses using the tree view without manual scrolling
- Visualising JSON data models as an interactive graph to understand key relationships
- Exporting formatted JSON diagrams as SVG or PNG for documentation and presentations
- Sharing readable, consistently indented JSON snippets in code reviews or Slack threads
- Catching JSON syntax errors (missing commas, trailing commas, unquoted keys) before runtime
Frequently Asked Questions
QIs my JSON data sent to a server?
No. All formatting, validation, tree parsing, and graph rendering happens locally inside your browser. No data is transmitted to any server at any point.
QWhat JSON specification does this formatter support?
Standard RFC 8259 JSON. JSONC (JSON with comments) and JSON5 are not supported. Remove comments before pasting, or preprocess with a tool such as strip-json-comments.
QCan it handle large JSON files?
Yes — the editor and formatter handle files comfortably up to several megabytes. Formatting runs in a dedicated Web Worker so even large inputs won't freeze the page. For files exceeding ~10 MB, a CLI tool such as jq is recommended.
QWhat is the Tree View?
The Tree tab renders your formatted JSON as a collapsible, expandable node tree. You can drill into nested objects and arrays one level at a time — ideal for deeply nested structures where scrolling through raw text is impractical.
QWhat is the Graph View and how do I export it?
The Graph tab renders your JSON as an interactive card-based hierarchical node graph, making the relationships between keys and values immediately visible. Use the SVG button to download a scalable vector file, or the PNG button for a high-resolution raster image.
See Also
- JSON MinifierStrip all whitespace from JSON for smaller production payloads
- YAML FormatterFormat YAML — a human-friendly config format that maps cleanly to JSON
- XML FormatterFormat XML documents with proper indentation and well-formedness validation
- CSV FormatterParse and preview CSV data as a sortable table, then export to JSON