Parse and format JSON from a pasted snippet or a dragged-and-dropped file, with live validation and structural stats.
Key Features of JSON Parser
- File Upload & Drag-and-Drop Drag and drop any .json file or select it from your device. The tool parses files locally in your browser.
- Real-Time Validation Identify syntax errors immediately with clear indicators pointing to the problem line.
- Structural Insights View live key counts, nesting depth, and byte size as you work.
- Syntax Highlighting Switch between light and dark themes using GitHub-style colors inside the Monaco editor.
- Custom Indentation Format with 2 or 4 spaces, or minify the code.
- One-Click Export Copy the result to your clipboard or download it as a formatted file.
- Auto-Repair Automatically repair common issues like single quotes, trailing commas, unquoted keys, Python literals, and comments.
JSON Parser Examples
Parsing an API Response File
Drop an API response file to check its keys, nesting depth, and size.
Input
{"user":{"id":101,"name":"Alice","roles":["admin","editor"]},"status":"active"}Output
{
"user": {
"id": 101,
"name": "Alice",
"roles": [
"admin",
"editor"
]
},
"status": "active"
}Auto-fixing Python-Style Dicts
Paste a Python dict with single quotes, True, False, or None. The tool converts them to valid JSON automatically.
Input
{'user': {'id': 101, 'active': True, 'role': None, 'verified': False}}Output
{
"user": {
"id": 101,
"active": true,
"role": null,
"verified": false
}
}How to Use JSON Parser
-
1. Paste or Upload JSON
Paste raw code or drop a .json file.
-
2. Choose Indentation
Choose 2 spaces, 4 spaces, or Minified.
-
3. Inspect & Export
Check formatted results and stats, then copy or download the file.
Common Use Cases for JSON Parser
- Inspecting Downloaded API Payloads Format and read API responses without opening an IDE.
- Validating Config Files Verify that package.json or settings.json files parse correctly.
- Debugging Nested Structures Spot overly nested configuration or data structures instantly.
- Converting Python Dictionaries to JSON Convert Python dictionaries to JSON without manual editing.
- Fixing Broken or Hand-Edited JSON Clean up hand-written JSON that has trailing commas or unquoted keys.
The Technical Details
The tool parses JSON directly in the browser using the native JSON.parse method. It formats outputs using JSON.stringify with your selected spacing.
The browser’s FileReader API reads file uploads as UTF-8 text before parsing. Monaco Editor and its built-in JSON worker handle syntax highlighting in the output panel.
To calculate the key count and nesting depth, the tool traverses the object tree recursively in linear time relative to the total number of items.
If native parsing fails, the repair pipeline runs automatically. It uses regular expressions to clean line endings, translate Python booleans and nulls, strip comments, remove trailing commas, and quote keys. A character-by-character state machine converts single quotes to double quotes while preserving escaped characters and strings. The status bar displays any repairs.
Frequently Asked Questions
What file types can I upload?
The file picker targets .json files and reads them as UTF-8 text. You can still paste content directly if your file has a different extension.
Is my data kept private?
Yes. Reading, parsing, and formatting run entirely inside your browser. No data leaves your machine.
Why does it show key count instead of total values?
Counting object keys is usually the best way to gauge schema complexity. Array structure shows up in the nesting depth instead.
Can I use this offline?
Yes. The parser works offline once loaded. Your browser caches the Monaco editor from a CDN on your first visit for offline access.
What happens if I drop a non-JSON file?
The tool reads files as text to parse them. If parsing fails, you will see the syntax error message.
Can it handle Python-style dicts?
Yes. It translates Python booleans to lowercase, changes None to null, and swaps single quotes to double quotes. The status bar lists any modifications.
What kinds of broken JSON can it fix?
It removes trailing commas, quotes keys, converts single quotes, translates Python literals, and strips both JavaScript and Python comments.