Bulk String Case Mutator
Paste a list of identifiers and instantly see every case variant — camelCase, PascalCase, snake_case, SCREAMING_SNAKE, kebab-case, Title Case, UPPER, and lower — all at once. Click any row to copy that format.
Bulk String Case Mutator
Paste identifiers — see every case variant instantly. Click a row to copy.
Click any row to copy that variant.
How to Use the Bulk Case Mutator
You have a list of variable names written in camelCase and your CSS linter demands kebab-case. Or you just inherited a codebase where half the identifiers use snake_case and the other half use PascalCase, and you need to standardise them all before a refactor. Paste every identifier into the input area, one per line, and the tool generates all eight case variants side by side so you can grab the exact format you need.
A React component uses backgroundColor in JavaScript but background-color in the stylesheet. Paste the camelCase name and the tool outputs background-color, BACKGROUND_COLOR, BackgroundColor, and every other variant. Click the kebab-case row to copy it straight into your CSS file.
A Postgres migration uses snake_case columns (user_profile, created_at) but the ORM expects camelCase (userProfile, createdAt). Paste the full column list and copy the camelCase block into your model definitions. Numbers and acronyms like HTTPResponse are preserved as separate tokens, so HTTPResponse becomes http_response in snake_case and HTTP_RESPONSE in SCREAMING_SNAKE.
A README references getUserProfile but the written sentence needs a readable form. The Title Case output gives Get User Profile, and the lower output gives get user profile. The tool handles small words correctly — a tale of two cities becomes A Tale of Two Cities with of kept lowercase.
A Python backend uses snake_case, a Go service uses PascalCase, and a TypeScript frontend uses camelCase. Paste the shared field names once and copy each format into the respective codebase. Unicode characters like e-acute are handled correctly, so cafe-au-lait becomes CafeAuLait in PascalCase.
How the Bulk Case Mutator Works
The tool splits each input identifier into word tokens using boundary detection on uppercase letters, underscores, hyphens, and dots, then reassembles those tokens into every enabled target format.
Tokenisation Rules
The tokenizer first replaces underscores, hyphens, and dots with spaces, then inserts a space before each uppercase letter preceded by a lowercase letter (camelCase boundary). A second pass splits runs of consecutive uppercase letters followed by a lowercase letter — so HTTPSRequest becomes HTTPS Request, not HTTP SRequest. The result is an array of lowercase word tokens: getUserProfile produces [get, user, profile], and fetch_api_data produces [fetch, api, data].
Title Case and Small-Word Rules
When generating Title Case, the first and last tokens are always capitalised regardless of their part of speech. Articles (a, an, the), short prepositions (of, in, on, at, to, for, by), and coordinating conjunctions (and, or, but, nor, yet, so) remain lowercase in middle positions. For example, get_the_value of two cities becomes Get the Value of Two Cities — the stays lowercase but Cities is capitalised because it is the last word.
Acronym Handling
Consecutive uppercase letters are treated as a single token. In PascalCase, acronyms remain fully uppercase within the word: parseHTTPSResponse becomes ParseHTTPSResponse. In camelCase, the first token is lowercased but later acronyms stay uppercase: the result is parseHTTPSResponse. In SCREAMING_SNAKE, every token is uppercased and joined with underscores: PARSE_HTTPS_RESPONSE.
Unicode and Locale-Aware Case Mapping
Case conversion uses the browser's built-in toLowerCase and toUpperCase methods, which handle Unicode correctly. Characters like e-acute, enye, and German eszett are lowercased and uppercased according to Unicode rules. The tool processes up to 500 input lines in a single render pass without blocking the main thread.
Frequently Asked Questions
How does Title Case handle small words like a, an, and, the?
Short articles, prepositions, and coordinating conjunctions are kept lowercase in Title Case output. The first and last words are always capitalised regardless. For example, get_the_value becomes Get the Value — the stays lowercase because it sits in the middle of the phrase.
Does the tool support Unicode and non-English characters?
Yes. Case conversion uses the browser's Unicode-aware case mapping, so characters like e-acute, enye, and German eszett are transformed correctly. Identifiers containing non-ASCII characters will produce accurate outputs in every enabled format.
What is the difference between Sentence case and Title Case?
Sentence case capitalises only the first letter of the first word, treating the input as a single sentence. Title Case capitalises the first letter of every significant word. For identifiers, Sentence case is less common but useful when generating human-readable labels from code-style names.
How are acronyms like HTTP, URL, and API handled?
The tokenizer detects runs of consecutive uppercase letters and preserves them as a single token. In PascalCase, an acronym remains fully uppercase within the word: parseHTTPSResponse becomes ParseHTTPSResponse. In camelCase, the first token is lowered but acronyms in later positions stay uppercase.
Can I paste multiple identifiers at once?
Yes. Each line in the input is treated as a separate identifier. All lines are processed in parallel and every enabled case format shows the full list. You can paste hundreds of lines and see them all converted simultaneously.
What happens with numbers and special characters in identifiers?
Numbers adjacent to letters are treated as separate tokens. For example, rgb2hex tokenizes to rgb, 2, hex. Underscores and hyphens are recognised as word delimiters and are not included in the output tokens. Special characters outside common word boundaries are stripped during tokenization.