PascalCase to snake_case converter
Paste PascalCase class or model names and get them back in lowercase snake_case.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter pascalcase names (one per line or inside text).
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Each PascalCase name is split into words at every change from a lowercase letter or digit to a capital, and before the last capital of an acronym that is followed by a lowercase letter. The words are then lowercased and joined with underscores (_). Symbols and spaces around the names are left as they are. Example: UserProfile becomes user_profile.
Example
Result: snake_case result: user_profile order_line_item xml_http_request; Names processed: 3.
UserProfile OrderLineItem XMLHttpRequest
user_profile order_line_item xml_http_request
Limits and caveats
- A name with no capital to mark the word break, such as username or an Arabic name, cannot be split.
- Digits stay attached to the letters before them, so item2Count is read as item2 and Count.
- Converting back may not restore the original exactly: an acronym such as HTML comes back as Html.
Questions about this tool
Where is this conversion used?
In Ruby on Rails, for example, the class UserProfile lives in user_profile.rb, and in Python modules are named in lowercase with underscores while classes stay in PascalCase.
How is XMLHttpRequest split?
Into XML, Http and Request, giving xml_http_request, because the last capital before a lowercase letter starts a new word.
Is a plural s added for table names?
No, only the writing style changes; turning User into users is a pluralisation rule that differs by framework and language.