Camel Case to Snake Case Converter

Turn camelCase identifiers such as userProfileImage into snake_case such as user_profile_image.

Free, private, and processed in your browser.

Detected: snake_case
snake_case output
user_profile_image_url

All naming formats

camelCase
userProfileImageUrl
PascalCase
UserProfileImageUrl
snake_case
user_profile_image_url
kebab-case
user-profile-image-url
CONSTANT_CASE
USER_PROFILE_IMAGE_URL
dot.case
user.profile.image.url
path/case
user/profile/image/url

Conversion happens locally in your browser. Your input is not sent to a conversion server.

Examples

InputOutput
userProfileImageuser_profile_image
createdAtcreated_at
apiResponseUrlapi_response_url

How this converter works

Paste text or an identifier above. The tool detects word boundaries and common separators, then formats the result using the selected naming convention.

  • Lower-to-upper case transitions are detected as word boundaries before underscores are inserted.
  • Tokens are normalized to lowercase and joined with underscores.

Common use cases

Convert JavaScript-style identifiers into Python, SQL, database-column, or serialization conventions.

Prepare camelCase object-property names for systems that require snake_case fields.