Text and Data Tools

snake_case Converter

Join normalized words with single underscores to generate snake_case names in batches.

Input Text

Result

Normalize naming styles to lowercase underscores, recognizing acronyms and existing camelCase boundaries.

Your input is processed only in your browser and is never uploaded to a server.

About This Tool

snake_case Converter is useful for variables, database fields, and configuration keys. It shares tokenization with the other two naming tools and recognizes helloWorld and XMLHttpRequest instead of merely replacing spaces.

How to Use It

  1. Enter a name or a list of field names on separate lines.
  2. Choose whether to convert each line independently; this is on by default.
  3. Click Convert and check the lowercase words and single underscores.
  4. Copy or download the output, then verify identifier validity in the target language.

Examples

  • Hello World → hello_world; helloWorld → hello_world.
  • XMLHttpRequest → xml_http_request.
  • multiple spaces → multiple_spaces; Café Name → café_name.

Rules and Limits

Shared tokenization recognizes letter-case boundaries, acronyms, and separators. Unicode-aware casing lowercases each word, which is then joined with a single underscore. Repeated separators do not create repeated underscores, and Chinese characters or other Unicode letters are not removed by an ASCII-only filter.

Common Uses

  • Organize Python variables or database columns.
  • Standardize configuration keys.
  • Convert camelCase properties in batches.

Privacy

Text processing, file reading, conversion, and previews all run locally in this browser. Input is not uploaded or automatically saved. No backend, database, online API, or third-party CDN is used. Copying and downloading also happen locally.

FAQ

What is snake_case?

Words are separated by underscores and are usually lowercase, as in user_name.

Can it convert existing camelCase?

Yes. Case boundaries split words, so helloWorld becomes hello_world.

Will multiple spaces produce multiple underscores?

No. Consecutive separators become word boundaries, and output uses just one underscore between adjacent words.

Are Chinese characters removed?

No. They are preserved, with underscores between explicitly separated words. The tool does not perform Chinese semantic segmentation or translation.

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