🗂️ JSON Formatter & Viewer
Paste JSON above to validate it automatically
What is a JSON Formatter?
JSON (JavaScript Object Notation) is the most widely used data exchange format in modern web development. However, raw JSON from an API or a log file is often minified into a single line, making it nearly impossible to read at a glance.
🗂️ This tool instantly formats, validates, and visualizes any JSON — no installation required.
Core Features
📐 Prettify & Minify
Prettify reformats compressed JSON with clean line breaks and indentation (2 or 4 spaces), so you can read nested structures instantly. Minify does the reverse — it strips all whitespace and outputs a compact single-line string, perfect for API requests or storage efficiency.
✅ Real-time Validation
As you type or paste JSON, the validator runs automatically. If your JSON is valid, a green indicator confirms it. If there is a syntax error, the error message shows the exact line number and column, so you can fix it immediately without guessing.
🌲 Interactive Tree View
Switch to the Tree View tab to explore your JSON as a collapsible hierarchy. Each node shows its key, value, and data type. Objects and arrays can be expanded or collapsed with a single click. Nodes deeper than 2 levels start collapsed by default, keeping the view clean even for deeply nested data.
⚡ Convenience Features
- Copy — one click to copy the entire JSON to your clipboard.
- Download — save the current JSON directly as a
.json file. - Load Sample — instantly load example JSON with various data types (strings, numbers, booleans, arrays, nested objects, null) to explore the tool.
Common Use Cases
- Debugging API responses — paste the raw response body to instantly read the structure and find the field you need.
- Validating configuration files — check
package.json, tsconfig.json, or any config file for syntax errors before deploying. - Preparing data for APIs — minify formatted JSON to reduce payload size when sending data over the network.
- Exploring unknown data structures — use Tree View to navigate deeply nested JSON without losing your place.
JSON Data Types
JSON supports six primitive data types, all visible in the Tree View with color coding:
■ String — text enclosed in double quotes: "hello"
■ Number — integer or decimal: 42, 3.14
■ Boolean — true or false
■ Null — represents an empty value: null
■ Object — key-value pairs: { "key": "value" }
■ Array — ordered list: [1, 2, 3]
* All processing happens entirely in your browser. Your JSON data is never sent to any server.
Frequently Asked Questions
Q. Can JSON have comments?
Standard JSON doesn't allow comments — only JSON5/JSONC do. This formatter is strict JSON, so comments raise errors.
Q. What errors does the validator catch?
Syntax errors (missing commas/brackets), duplicate keys, invalid escapes — with line and column pointers.
Q. Does it handle large JSON?
Up to browser memory limits (~50-100MB). Beyond that the tab may freeze; split the data.
Q. How do I use the tree viewer?
Collapse and expand nested objects/arrays to read structure at a glance — great for big payloads.
Q. Is my data sent anywhere?
No. Everything parses locally; secrets like API keys never leave the tab.
Q. Can it convert YAML or XML?
JSON only — use a dedicated tool for YAML/XML.
