Case Converter Online
Paste an identifier or a whole list of them and get every naming convention back, including the awkward ones like CONSTANT_CASE and kebab-case. Acronyms survive the round trip.
How it works
The trivial part of this job is applying a separator and a capitalisation rule. The part that actually matters is finding the word boundaries in whatever you were handed. Code arrives in every convention at once — a userId field from one API, a user_id column from the database behind it, and User Profile in the interface — and a converter that cannot read all three leaves you re-checking by hand every time.
This one reads all of them. It splits on a capital that follows a lowercase letter or a digit, so userProfile becomes two words. It splits a run of capitals that is followed by a capitalised word, so parseHTTPServer correctly yields parse, HTTP and Server rather than mangling the acronym. And it splits on any run of non-alphanumeric characters, so user_id-2 and user.id work too.
Acronyms surviving the round trip is where most converters fall down. Converting parseHTTPServer to snake_case gives parse_http_server, and converting that back gives parseHttpServer with the acronym intact rather than flattened into Http. A run of capitals is treated as one word, and only its first letter changes when that word starts a camelCase identifier.
Pasting a list works as well. Each line is converted independently and blank lines are preserved in place, so you can paste a column of database headers and copy back a matching column of JavaScript properties without doing them one at a time.
Pick the target style from the dropdown above the panes. The left pane is always your text and the right pane is always the result, so you can move between styles without losing what you pasted.
Use the Case Converter
Paste identifier on the left to see the result.Runs entirely in your browser — nothing you paste is uploaded or logged.
Worked examples
Real input and the exact output this page produces.
Example 1
Identifier
user profile URL
Any case
userProfileURL
Example 2— snake_case
Identifier
parseHTTPServer
Any case
parse_http_server
Example 3
Identifier
user_id
created_at
is_active
Any case
userId
createdAt
isActive
Frequently asked questions
How does it handle acronyms like URL and ID?
A run of capitals is treated as a single word. userProfileURL becomes user_profile_url, and converting that back gives userProfileURL with the acronym intact rather than flattened into Url.
Can I convert a whole list at once?
Yes. Every line is converted independently and blank lines are kept in place, so you can paste a list of column names and copy the result straight back.
What happens to digits?
Digits stay attached to the word they follow, so version2Value becomes version2Value in camelCase and version_2_value in snake_case.
Is the conversion reversible?
Mostly. Going to snake_case and back to camelCase round-trips cleanly for most identifiers. Styles that flatten case information, such as UPPERCASE, cannot be reversed because the boundaries are gone.
Related tools
Others doing similar work.