Case Converter: Upper, Lower, Title, Sentence & More
Convert text to UPPER CASE, lower case, Title Case, Sentence case, Capitalized Case, or Inverse Case. Normalize whitespace to a single space or double space between sentences. Output updates live as you type. Free, runs in your browser—no sign-up required.
What is a case converter?
A case converter (or text case converter) changes the capitalization and spacing of text. You can convert to uppercase (all capitals), convert to lowercase (all small letters), Title Case (first letter of every word), Sentence case (first letter of each sentence only), Capitalized Case (only the first letter of the whole text), and Inverse Case (swap upper and lower for each letter). This tool also normalizes whitespace: Normalized with Single Space trims and collapses every run of spaces, tabs, and newlines to one space; Normalized with Double Space does the same and then puts two spaces after sentence-ending punctuation (. ! ?). Use it for headings, pasted text cleanup, citations, or consistent formatting without writing code.
Select a transformation in the tool above; the output panel updates in real time as you type or paste. The last 5 conversions are saved in your browser so you can reapply a case quickly. All processing happens locally—no data is sent to a server—so you can use it on sensitive or confidential text.
How to convert text to uppercase, lowercase, or title case (step by step)
To convert text to uppercase or convert to lowercase, paste your text into the input panel and click UPPER CASE or lower case. The output shows the result immediately and updates live as you edit. For Title Case, the tool capitalizes the first letter of each word (e.g. "the quick brown fox" → "The Quick Brown Fox"). For Sentence case, it capitalizes only the first letter of each sentence—split on periods, question marks, and exclamation points—so body paragraphs stay readable (e.g. "HELLO. HOW ARE YOU?" → "Hello. How are you?"). Capitalized Case makes only the very first character uppercase and the rest lowercase (e.g. "HELLO WORLD" → "Hello world"), useful for single-line labels or titles where you don’t want every word capitalized.
UPPER CASE = all caps. lower case = all lowercase. Title Case = first letter of every word. Sentence case = first letter of each sentence.
Inverse Case flips each letter: uppercase becomes lowercase and lowercase becomes uppercase (e.g. "Hello World" → "hELLO wORLD"). Use it for stylistic effect or to quickly toggle case. If you only need to capitalize first letter of the entire block, choose Capitalized Case; for the first letter of every word, choose Title Case.
Sentence case vs Title Case vs Capitalized Case
Sentence case capitalizes the first letter of each sentence and leaves the rest of each sentence lowercase. It’s the standard for articles, essays, and body copy (e.g. "The quick brown fox. It jumps over the lazy dog."). Title Case capitalizes the first letter of every word and is used for book titles, headings, and headlines (e.g. "The Quick Brown Fox Jumps Over The Lazy Dog"). Style guides differ on whether to capitalize small words (a, the, of)—this tool capitalizes every word for consistency. Capitalized Case (sometimes called "capitalize first letter only") uppercases only the first character of the whole text and lowercases the rest (e.g. "HELLO WORLD" → "Hello world"). Use it when you want one leading capital and no other changes, such as for a single headline or label.
Choose the transformation that matches your goal: convert to uppercase for emphasis or accessibility, convert to lowercase to fix accidental caps or normalize pasted text, Title Case for titles, Sentence case for paragraphs, and Capitalized Case when only the first letter should be capital.
Normalized with Single Space and Double Space
Normalized with Single Space trims leading and trailing whitespace and replaces every run of spaces, tabs, and newlines with a single space. So " hello world \n\n " becomes "hello world". It does not change letter case—only whitespace. Use it to clean pasted text, fix double spaces, or prepare copy for systems that expect one space between words.
Normalized with Double Space first applies the same single-space normalization, then ensures two spaces after each sentence-ending character (. ! ?). That gives you one space between words and two spaces between sentences—common in legacy typing and some style guides. Both options help you normalize spaces in text without touching capitalization.
Common use cases: who uses a case converter?
Writers and editors use it to fix pasted text (e.g. convert to lowercase or Sentence case), format headings (Title Case), or normalize spacing. Students and educators use it to meet formatting requirements (e.g. "title case for headings") or to see how different cases look. Developers and content creators use it to normalize user input, fix ALL CAPS comments, or prepare strings for display. Accessibility sometimes calls for uppercase labels or headings; converting to uppercase in one click is faster than retyping. Anyone who needs to convert to uppercase, convert to lowercase, or apply Title Case or Sentence case without manual editing can use this tool. All conversions run in your browser—no data is sent to a server—so it’s safe for sensitive or confidential text.
Inverse case and live update
Inverse Case (or invert case) swaps uppercase and lowercase for every letter: A→a, a→A. Numbers and punctuation are unchanged. Use it for stylistic effect (e.g. "aLtErNaTiNg" style), testing how your UI handles mixed case, or quickly flipping text that was pasted in the wrong case. Once you select any transformation—UPPER CASE, lower case, Title Case, Sentence case, Capitalized Case, Inverse Case, or either normalize option—the output panel updates in real time as you type or paste. You can switch transformations at any time; the last 5 conversions are stored in your browser so you can reapply them with one click.
Case Converter FAQ
? How do I convert text to uppercase?
Paste or type your text in the input panel, then click UPPER CASE. The output panel shows the same text in all capitals and updates live as you edit. You can also use it to convert to lowercase by clicking lower case instead. No manual retyping required—the tool applies the transformation instantly.
? How do I convert to lowercase?
Paste your text into the input panel and click lower case. Every letter is converted to lowercase; the output updates in real time as you type. Use it to fix accidental caps lock, normalize pasted text, or prepare copy for systems that expect lowercase. To capitalize only the first letter of the whole text, use Capitalized Case instead.
? What is the difference between Title Case and Sentence case?
Title Case capitalizes the first letter of every word (e.g. "The Quick Brown Fox"). Sentence case capitalizes only the first letter of each sentence (e.g. "The quick brown fox. It jumps over the dog."). Use Title Case for titles, headings, and headlines; use Sentence case for paragraphs and body copy. This tool supports both so you can switch with one click.
? What is Capitalized Case?
Capitalized Case makes only the first character of the entire text uppercase and the rest lowercase. So "HELLO WORLD" becomes "Hello world". It is different from Title Case (every word capitalized) and Sentence case (each sentence capitalized). Use it when you want to capitalize first letter of the text only—for example, a single headline or label.
? What is Inverse Case (invert case)?
Inverse Case swaps uppercase and lowercase for each letter: uppercase becomes lowercase and lowercase becomes uppercase. So "Hello World" becomes "hELLO wORLD". Numbers and punctuation stay the same. Use it for stylistic effect, testing, or to quickly flip text that was pasted in the wrong case. Click Inverse Case in the tool to apply it; the output updates live as you type.
? What does Normalized with Single Space do?
It trims leading and trailing whitespace and replaces every run of spaces, tabs, and newlines with a single space. So multiple spaces between words become one space, and line breaks are turned into spaces. It does not change letter case—only whitespace. Use it to clean pasted text, remove extra spaces, or normalize spacing. For two spaces after sentences, use Normalized with Double Space instead.
? Does the output update as I type?
Yes. Once you select a transformation (e.g. UPPER CASE, lower case, Title Case, or Sentence case), the output panel updates in real time as you type or paste in the input. You can change the transformation at any time; the last 5 conversions are saved in your browser history so you can reapply them with one click. All processing runs locally—no data is sent to a server.