JSON Key Case Converter

How to use

1. 1Paste any valid JSON document into the input on the left. Click Load sample to see a worked example.
2. 2Pick the target style (camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, kebab-case, COBOL-CASE, or dot.case).
3. 3Choose deep recursive scope to rewrite keys at every nested level, or top level only to leave nested objects untouched.
4. 4Toggle Preserve leading underscore and Preserve common acronyms based on your codebase conventions.
5. 5Pick an output format (2 spaces, 4 spaces, tab, or minified) and click Copy output to grab the result.

About this tool

JSON Key Case Converter rewrites every property name of a JSON document into the naming convention your API, client, or database expects, while leaving the values, types, and array order untouched. Paste any valid JSON and pick a target style: camelCase for JavaScript clients, snake_case for Python or Ruby backends, kebab-case for HTTP-style identifiers, PascalCase for .NET conventions, SCREAMING_SNAKE_CASE for environment-style constants, COBOL-CASE for legacy systems, or dot.case for nested config files. The tool understands the source style automatically. The same tokenizer splits user_id, userId, USER_ID, user-id, or User.Id into the same logical tokens (user and id), then re-emits them in the chosen target style. Common acronyms like URL, API, JSON, JWT, and UUID can be preserved as a single token so userId becomes USER_ID and not USER_I_D when you toggle styles. A leading underscore (the Python convention for private fields) can be preserved so _internalFlag stays prefixed after conversion. Choose deep mode to rewrite keys at every nested level, or top level only to rewrite an envelope without touching the data inside. The output panel highlights how many keys were renamed and warns when two source keys collapse into the same target name. Output formatting offers 2-space, 4-space, tab, or minified JSON. Parsing and traversal use the native JSON parser, so the JSON you paste here never leaves your browser.

Free to use. Works in your browser. No signup, no login.