Case Converter
Use this free online Case Converter to switch any block of text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case, kebab-case and Inverse Case in one click. It is useful for writers fixing a paragraph that arrived in CAPS, programmers renaming variables, marketers preparing headlines, students cleaning notes copied from a PDF, and anyone who has ever pasted text into a form and noticed it is the wrong shape. Drop your text into the box, click the case you want, and copy the result back out. Nothing is uploaded — every transformation happens locally in the browser, so even confidential drafts stay on your device.
Available Modes
UPPERCASE turns every letter capital, lowercase makes everything small, Title Case capitalizes the first letter of each word, Sentence case capitalizes only the first letter of each sentence, and Alternating/Inverse modes are creative styling options.
How to Use This Case Converter
Converting case takes two clicks — paste and pick.
- Paste or type your text into the input area.
- Click the button for the case you want — UPPERCASE, lowercase, Title Case, Sentence case or one of the programming styles.
- Read the converted output below the buttons.
- Click Copy to copy the converted text to your clipboard.
- Click Clear to wipe the input and start over.
How This Case Converter Works
Each case style follows a different rule. UPPERCASE applies the JavaScript toUpperCase() method, which respects most Unicode locales. lowercase is its mirror via toLowerCase(). Title Case capitalises the first letter of every word, leaving the rest lowercase. Sentence case capitalises the first letter of every sentence — detected by the period, question mark or exclamation point that ended the previous sentence — and lowercases the rest. Inverse Case flips each character: lowercase letters become uppercase and vice versa. The programming-friendly conversions involve a small extra step: camelCase strips spaces and capitalises every word after the first; snake_case lowercases everything and joins words with underscores; kebab-case is the same with hyphens. Punctuation is preserved in every mode so commas, full stops and quotation marks stay where they belong. Because the conversions are pure string operations the tool can handle very large blocks of text without slowing down the browser, and the absence of any server upload means even confidential drafts can be reformatted safely.
Last updated: May 2026.
Frequently Asked Questions
What's the difference between Title Case and Sentence case?
Title Case capitalises the first letter of each word. Sentence case capitalises only the first letter of each sentence and proper nouns.
Why doesn't Title Case skip "and" or "of"?
This is a simple Title Case that capitalises every word. Style guides differ on which "small words" to lowercase — for AP-style or Chicago-style results you'll need to manually adjust afterwards.
Does the converter preserve numbers and punctuation?
Yes — only alphabetic characters are affected. Numbers, spaces, and symbols remain exactly as you entered them.
Why use sentence case instead of title case?
Sentence case is easier to scan and feels less promotional. Many modern UI style guides (Google, Microsoft) prefer it for buttons and labels.
Are there accessibility concerns with ALL CAPS?
Yes. Screen readers may pronounce ALL CAPS letter-by-letter, and long all-caps text is harder to read for most users. Reserve uppercase for short emphasis only.