Pascal Case to Snake Case Converter

Turn PascalCase 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.

  • Capital-letter boundaries are split into separate words before formatting.
  • The resulting words are lowercased and joined with underscores.

Common use cases

Map class or type names into database, serialization, or Python-style field names.

Normalize PascalCase identifiers when generating API keys, fixture fields, or SQL-facing names.

Related tools and guides

Snake Case → Camel CaseCamel Case → Snake CaseSnake Case ConverterSnake Case → Kebab CaseSnake Case → Pascal CasecamelCase vs snake_case