Case Converter
Paste your text and switch it to UPPERCASE, lowercase, Title Case or Sentence case — instantly, right in your browser.
What each case style does
UPPERCASE turns every letter into capitals — headings, acronyms, warnings. lowercase removes all capitals, useful for cleaning shouty text or normalizing data before a comparison. Title Case capitalizes the main words the way book and article titles do, keeping short connectors (a, of, to, and) small. Sentence case capitalizes only the first word of each sentence — the style of normal prose. aLtErNaTiNg and InVeRsE case are novelty styles for memes and social posts: alternating flips every second letter, inverse swaps whatever is already there.
camelCase, snake_case and kebab-case for developers
Beyond writing styles, this converter also produces the three identifier styles programmers use daily: camelCase (first word small, each next word capitalized — JavaScript variables), snake_case (words joined with underscores — Python, SQL, config keys) and kebab-case (words joined with hyphens — URLs, CSS classes, file names). Each line converts independently, so you can paste a list of labels and get a list of identifiers back. Punctuation is stripped and numbers are kept, so “API response time (ms)” becomes apiResponseTimeMs, api_response_time_ms or api-response-time-ms.
Fixing text stuck in ALL CAPS
The most common rescue job: a paragraph typed with Caps Lock on. Pasting it and pressing Sentence case rewrites it as normal prose in one click — first letters of sentences capitalized, everything else lowered, and the pronoun “I” restored in English. That is usually faster than retyping and safer than lowercase alone, which would also flatten names and acronyms you then have to fix by hand. For names and titles that should keep their capitals, run Sentence case first and touch up the few proper nouns after.
Case rules differ by language — this tool respects yours
Casing is not the same in every language, and naive converters corrupt text that isn’t English. Turkish and Azeri distinguish dotted İ/i from dotless I/ı — uppercasing “istanbul” must give “İSTANBUL”, not “ISTANBUL”. Greek lowercases a final sigma differently (Σ → ς at the end of a word). This converter uses your page language’s real casing rules, so the localized versions of this page convert correctly for their scripts — one of the reasons to prefer a locale-aware tool over a generic one.
When to use Title Case vs Sentence case
House styles disagree, but the practical rule: Title Case for book titles, essay headings in APA style, and marketing headlines (This Is a Headline); Sentence case for news headlines, UI labels, and most web writing (This is a headline). Sentence case reads calmer and is easier to keep consistent; Title Case signals formality. If you need the strict per-style rules — APA, Chicago, MLA and AP treat short prepositions differently — use our dedicated Title Case Converter, which implements each style’s word list.
Private by design, and built for repeat use
Conversion happens entirely in your browser with JavaScript — the text is never uploaded, stored or logged, which makes it safe for contracts, unpublished drafts and anything confidential. The converter remembers your last-used mode on this device, keyboard users can Tab between the buttons, and the result stays in the same box so you can chain conversions (lowercase first, then Title Case) or send the text straight to the Word Counter or Grammar Checker with one click.
Is my text uploaded anywhere?
No. The conversion runs entirely in your browser with JavaScript — nothing is sent to a server, stored, or logged.
What does Title Case capitalize?
The first letter of every word, except short connectors (a, an, the, and, or, of, to, in, on, at, for, nor, but) unless they start the sentence — the style used for headlines and titles.
What is Sentence case?
The first letter of each sentence capitalized and the rest lowercased — standard prose. The converter detects sentence ends at . ! and ?, and keeps the pronoun "I" capitalized.
Does it work for long documents?
Yes — there is no length limit, because the text never leaves your device. Very long texts convert as fast as short ones.
How do I change uppercase to lowercase?
Paste your text and click lowercase — every letter converts from uppercase to lowercase instantly. To go the other way (lowercase to uppercase), click UPPERCASE.
Can I fix text stuck in ALL CAPS?
Yes — this is the fastest all caps converter fix: paste the text and click Sentence case. It changes caps to lowercase while keeping the first letter of each sentence (and the word “I”) capitalized, so you don’t have to retype anything.
What are camelCase and snake_case?
They’re naming styles used in programming: camelCase joins words with each new word capitalized (myVariableName), while snake_case joins them with underscores (my_variable_name). Paste any phrase and click either button to convert it — each line converts separately.