Case Converter
Convert text between sentence case, lower case, UPPER CASE, Capitalized Case, alternating case, Title Case, and Inverse Case — instantly, entirely inside your browser.
What is a Case Converter?
A case converter rewrites text into a different letter-casing style with one click, instead of retyping it by hand or fighting with a word processor's autocorrect. It's useful any time text was typed with the wrong caps lock state, pasted from a source with inconsistent casing, or needs to match a specific style — a heading in Title Case, a constant in UPPER CASE, or a sentence that should start with a capital letter and nothing else.
It's built for writers cleaning up pasted text, developers formatting constants or identifiers, students fixing an accidentally-caps-locked paragraph, and anyone who needs a quick, reliable case transformation without a full text editor.
GuideHow to use it
How each case style works
Sentence case lowercases everything, then capitalizes the first letter after every sentence-ending punctuation mark. lower case and UPPER CASE simply lowercase or uppercase every character. Capitalized Case capitalizes the first letter of every word, no exceptions. Title Case does the same but keeps common short words — like "a," "and," "of," and "the" — lowercase unless they're the first or last word, matching typical heading style. aLtErNaTiNg cAsE alternates upper and lower case by character position, and InVeRsE CaSe flips whichever case each character already is, uppercase becoming lowercase and vice versa.
Why it helpsFeatures & benefits
Why this runs entirely in your browser
Whatever gets typed or pasted here stays in the tab. Every case transformation runs in JavaScript locally, so nothing is ever uploaded, logged, or sent to a server, and it keeps working offline once the page has loaded.
A note on Title Case
Title casing rules vary slightly between style guides — some capitalize every word four letters or longer, others use a fixed list of short words to keep lowercase. This tool uses a common, general-purpose list of short connecting words, which covers most everyday headings well but may differ in edge cases from a specific publication's house style.
Frequently asked questions
A few things people usually want to know before using this.
Capitalized Case capitalizes every word with no exceptions. Title Case keeps short connecting words like "a," "and," and "of" lowercase, matching typical heading style.
Alternating case applies an up-down-up-down pattern based on character position, ignoring the original casing. Inverse case flips whatever case each character already has.
Yes. Each click applies to whatever text is currently in the box, so you can chain transformations if needed.
Yes. Use the download button to save the current text as a .txt file.
No. All conversion happens locally in your browser. Nothing typed here is sent to a server, stored, or shared.