Snake_case writes compound words in lowercase separated by underscores, like 'my_variable_name'. It is common in Python, Ruby and database column names.

How does it split camelCase words?

A word boundary is inserted before each uppercase letter, so 'myVariableName' becomes the words 'my', 'variable', 'name', which join with underscores to 'my_variable_name'.

Does it handle PascalCase and acronyms?

Yes. PascalCase like 'MyClassName' converts to 'my_class_name'. Acronyms such as 'parseHTMLString' are split sensibly into 'parse_html_string' rather than splitting every capital letter.

Can I paste multiple words or whole lines?

Yes. The converter also splits on spaces, hyphens and other separators, so mixed input still converts cleanly to a single snake_case token.

Why use snake_case instead of camelCase?

It is the convention in Python, Ruby, Rust and most SQL databases. Matching the target language's style keeps code idiomatic and avoids linter warnings when you port identifiers between ecosystems.

Is my text uploaded anywhere?

No — the conversion happens entirely in your browser and nothing is sent over the network.

Camel Case to Snake Case Converter

This converter turns camelCase or PascalCase identifiers into snake_case — the naming style used in Python, Ruby, Rust and SQL column names. Paste a name like myVariableName and get my_variable_name instantly. It is built for developers porting variable names between languages, renaming database columns, or normalising config keys, and it runs entirely in your browser.

How it works

The tool finds the word boundaries inside the identifier, lowercases each word, and joins them with underscores. It inserts a split in two places: between a lowercase or digit followed by an uppercase letter (a → B), and between a run of capitals and a following capitalised word, so acronyms stay intact. It then also splits on any non-alphanumeric separator. Each resulting word is lowercased and the pieces are joined with _.

Example

Input	Words detected	Output
`myVariableName`	my · variable · name	`my_variable_name`
`MyClassName`	my · class · name	`my_class_name`
`parseHTMLString`	parse · html · string	`parse_html_string`
`getUserID2`	get · user · id2	`get_user_id2`

So parseHTMLString becomes parse_html_string, with the HTML acronym handled correctly rather than split letter by letter.

Everything runs in your browser, so your code never leaves your machine.