Convert snake_case to camelCase
Consuming a Python or Ruby API from JavaScript usually means mapping snake_case fields to camelCase properties. This converter splits identifiers on underscores, lowercases the first word, and capitalizes the rest — the standard camelCase convention in JavaScript, Java, and Swift.
user_name created_at http_server_error is_active
userName createdAt httpServerError isActive
Try it with your own data
How to convert snake_case to camelCase
- Split the identifier on each underscore (user_name → user, name).
- Lowercase the first word and capitalize the first letter of every following word.
- Join the words back together with no separator.
Frequently asked questions
What is the difference between camelCase and PascalCase?
camelCase starts with a lowercase letter (userName); PascalCase capitalizes the first word too (UserName). JavaScript uses camelCase for variables and PascalCase for classes and React components.
Should JSON API fields be camelCase or snake_case?
There is no single standard — Google's JSON style guide says camelCase, while many Python and Rails APIs emit snake_case. Pick one convention per API and convert at the boundary.
How does the converter know where words start and end?
It splits on separators (underscores, hyphens, spaces) and on lowercase-to-uppercase boundaries, keeping acronym runs together — so HTTPServerError splits into HTTP, Server, Error regardless of the input convention.
Can I convert many identifiers at once?
Yes — put one identifier or phrase per line and every output format converts the whole list, ready to copy as a block.