How to convert json keys from camelcase to snake_case
- Step 1Paste the camelCase JSON — Paste the JavaScript/TypeScript API response JSON with camelCase keys: { "userId": 1, "firstName": "Alice", "address": { "postalCode": "10001" } }.
- Step 2Select the conversion direction — Choose camelCase →’ snake_case for Python/database targets, or snake_case →’ camelCase for JavaScript targets.
- Step 3Apply the conversion — Click Convert. The output has all keys recursively converted: { "user_id": 1, "first_name": "Alice", "address": { "postal_code": "10001" } }.
- Step 4Use in your Python or Rails code — The converted JSON is ready for Python's json.loads() into a snake_case dict, or for a Rails controller that expects params with snake_case keys. No manual mapping required.
Frequently asked questions
How are acronyms handled — for example, ID, URL, or API?+
The converter treats consecutive uppercase letters as a word boundary. userId →’ user_id (correct). APIKey →’ api_key (correct). HTMLParser →’ html_parser (correct). If your codebase has non-standard conventions for specific acronyms, use the manual rename mapping mode to override those specific keys after the automatic conversion.
Can I implement this conversion in Python?+
Yes. Use the humps library: pip install pyhumps. Then: import humps; snake_case_dict = humps.decamelize(camel_case_dict). Or use a one-liner with re: import re; snake = re.sub(r'(?<!^)(?=[A-Z])', '_', key).lower().
Is the JSON payload transmitted to JAD Apps?+
No. Conversion runs entirely in your browser. JSON payloads are never transmitted to JAD Apps servers.
Privacy first
Conversion runs locally in your browser. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.