UPPERCASE, lowercase, Title Case, Sentence case, camelCase, or snake_case — pick your format.
Paste or type text into the left box, then press the format you want. The result lands in the right box, and the copy button puts it on your clipboard without touching your original. Nothing is sent anywhere; the conversion runs in the page.
Six formats are offered because there are six jobs. UPPERCASE and lowercase are mechanical. Title Case is for headlines and headings. Sentence case is for body text that arrived shouted. camelCase and snake_case are for variable names, file names and database columns, where a space is not allowed. Pick by what the text is for, not by which button looks satisfying.
Start with the lower-case phrase the war of the worlds and see what each format does to it:
| Format | Result |
|---|---|
| Title Case | The War of the Worlds |
| Sentence case | The war of the worlds |
| camelCase | theWarOfTheWorlds |
| snake_case | the_war_of_the_worlds |
Title Case keeps of and the lower-case because they are minor words, and it capitalises both ends of the phrase regardless. That is why of at the start would come out as Of. camelCase glues the words together with no separator and raises the first letter of everything after the first word, which is why the result reads as one token. snake_case replaces the spaces with underscores and leaves every letter low.
Sentence case is the format that surprises people. It lower-cases the whole string first, so a capitalised proper noun in the middle of a sentence comes back lower-case: feed it we drove to Paris in June and you get We drove to paris in june. It also capitalises whatever follows a full stop, question mark or exclamation point, which is usually right and occasionally wrong for abbreviations. Check names and places before you paste the result into anything published.
Title case is genuinely contested. Newspaper style keeps short prepositions and conjunctions down; some book styles capitalise every word. The list this page uses — a, an, the, and, but, or, for, nor, on, at, to, from, by, of, in, with — is the common newspaper set, and it will differ from your house style on words like up and over. Treat the button as a first pass, not a ruling.
For code identifiers, pick one convention and stay with it. camelCase for JavaScript variables and snake_case for Python or database columns is the ordinary split; the tool does not add type prefixes or fix names that start with a digit.
UPPERCASE, lowercase, camelCase and snake_case operate on the raw string, so breaks survive. Title and sentence case split on spaces and will collapse the layout of a list.
Sentence case lower-cases everything before re-capitalising the start, so an acronym like NASA becomes nasa. Title case has the same effect on any word that is not first or last. Fix acronyms by hand afterwards.
No. The conversion is a few string operations in the page, so the text never leaves the browser tab.
snake_case or lowercase with hyphens. Spaces in file names break links and scripts; underscores are safe on every system this site has been tested on.
Paste as much as you like, but the output box is one text area. For long documents, convert section by section so you can read what changed.
Title case here is a house list, not a published style manual. Programming conventions are just conventions.
Last updated: November 2, 2026. Reviewed by David Liu.