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Parse & Format JSON in Python

Parse, format, and manipulate JSON data using Python online for free. Validate JSON, pretty-print, and transform data structures — no installation needed.

main.py

Ln 1, Col 1Spaces: 4

Python 3.13 (Pyodide)

Hit Run to see output here.

What You Get

Parse & serialize JSON

Pretty-print output

Validate JSON data

Transform data structures

JSON Examples

Custom Encoder

import json
from datetime import datetime

class DateEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime):
            return obj.isoformat()
        return super().default(obj)

data = {"event": "meeting", "when": datetime(2024, 3, 15, 14, 30)}
print(json.dumps(data, cls=DateEncoder, indent=2))