Case Converter
Convert text between UPPERCASE, lowercase, Sentence case, Title Case, and more — instantly, in your browser, with correct Unicode handling.
A case converter changes text between uppercase, lowercase, sentence case, title case, and more. Paste text into 99digest’s case converter and click a style — conversion happens instantly in your browser, with correct handling of accents and special characters.
How case conversion works
Sentence case capitalizes the first letter after each sentence boundary and treats a standalone “i” as “I” — matching standard English writing conventions, not just a blind first-letter capitalization.
Title Case here follows a quick, Chicago-style default: every word is capitalized except small words — a, an, the, and, but, or, nor, for, so, yet, at, by, in, of, on, to, up, as, if — unless that word is first or last in the text. If you need a different style guide’s rules (AP, MLA), that’s a separate, more precise tool.
Uppercase and lowercase conversion is locale-aware — for example, German “ß” correctly becomes “SS” in uppercase, not a broken character.
A limit of sentence case
Sentence boundaries are found with the Unicode text-segmentation rules, which do not start a new sentence when a full stop is followed by a lowercase word. Text that is already lowercase, such as “the quick brown fox. it jumps over the lazy dog”, keeps “it” in lowercase; question and exclamation marks work normally, so “hello world! how are you? i am fine” becomes “Hello world! How are you? I am fine”. Text in capitals, such as “THE QUICK BROWN FOX. IT JUMPS.”, converts well. For lowercase input, capitalise the first word of later sentences by hand. See the case guide and sentence case vs title case.
FAQs
What is sentence case?
Sentence case capitalizes only the first letter of each sentence (and the word “I”), leaving everything else lowercase — the way normal prose is written.
What’s the difference between Title Case and Capitalized Case?
Title Case follows the small-words list above, so short connecting words like “and” or “of” stay lowercase unless they’re first or last. Capitalized Case simply capitalizes every single word, with no exceptions.
Which words stay lowercase in Title Case?
a, an, the, and, but, or, nor, for, so, yet, at, by, in, of, on, to, up, as, if — unless that word is the first or last word in the text, in which case it’s always capitalized.
Does it handle accents and special characters correctly?
Yes. Case conversion is locale-aware, so accented letters convert correctly, and known special cases like German “ß” (which becomes “SS” in uppercase) are handled as documented, not silently broken.
Is there a keyboard shortcut for this in Word or Google Docs?
Microsoft Word has a built-in shortcut (Shift+F3) that cycles through UPPERCASE, lowercase, and Capitalize Each Word. Google Docs doesn’t have a built-in shortcut, but offers case options under Format → Text.
Is my text uploaded anywhere?
No. This tool runs entirely in your browser — your text is never sent to a server, uploaded, or stored anywhere.