Free Case Converter
Change text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, and more in one click. Free, unlimited, and 100% private.
A case converter changes the letter case of your text — to UPPERCASE, lowercase, Title Case, Sentence case, and more — in one click, without retyping. Humanit’s free case converter also offers camelCase, snake_case, and kebab-case for developers, and runs entirely in your browser so nothing is uploaded.
How it works
- 1Paste your text. Type or paste your text into the case converter above.
- 2See results instantly. The numbers update live as you type — there’s no button to press.
- 3Edit and re-check. Tweak your text and watch the results change in real time.
Every case in one click
Paste your text, click a case, and it transforms in place — then copy it out. Sentence case capitalizes the first letter of each sentence; Title Case capitalizes each major word (skipping small words like “a”, “of”, and “the”); Capitalized Case capitalizes every word. UPPERCASE and lowercase do exactly what they say.
Cases for developers
camelCase, snake_case, and kebab-case convert a phrase into a single identifier — handy for variable names, file names, database columns, and URL slugs. “User profile image” becomes userProfileImage, user_profile_image, or user-profile-image instantly.
Fix CAPS LOCK mistakes fast
Typed a whole paragraph with Caps Lock on? Paste it and hit Sentence case to fix it in one click instead of retyping. The same trick rescues text pasted from a PDF or a shouting email.
Title Case is not one rule — it depends on the style guide
This is the part almost no converter explains, and it is why two "correct" title-case tools can disagree about the same headline. AP style capitalises words of four letters or more, so it writes "A Guide to Writing With AI" — "With" is capitalised because it has four letters. Chicago style goes by part of speech instead and lowercases all prepositions regardless of length, giving "A Guide to Writing with AI". APA follows the four-letter rule like AP but also capitalises the first word after a colon. MLA lowercases articles, prepositions, and coordinating conjunctions unless they start or end the title. None of these is wrong — they are different conventions, and the one that matters is whichever your publication, journal, or CMS uses. This tool applies the common four-letter convention; if you are writing to Chicago, check prepositions like "with", "from", and "into" by hand.
Why the converter cannot always fix ALL-CAPS text perfectly
Converting uppercase down to sentence case means guessing information the capitals destroyed. "I MET JOHN BROWN IN MARCH" becomes "I met john brown in march" — the proper nouns are gone, because nothing in the input distinguishes a name from a common word. There is no way around this: uppercasing is lossy, and the original capitalisation cannot be recovered from the result. Expect to re-capitalise names, places, months, and brands by hand after a sentence-case conversion of shouted text. Everything else — the first letter of each sentence, the "I" — is handled for you.
Which case to use for filenames and URLs
For URL slugs, kebab-case is the convention and it is not just taste: hyphens are treated as word separators by search engines while underscores historically were not, so "ai-text-rewriter" reads as three words and "ai_text_rewriter" risks reading as one. For filenames, lowercase kebab-case avoids the case-sensitivity trap where a file works on your Mac and 404s on a Linux server. In code, follow the language: camelCase for JavaScript variables, snake_case for Python and SQL columns, PascalCase for class names in most languages.
Free, unlimited, and private
The case converter is free with no sign-up and no limit on how much text you process. Because it runs entirely in your browser, your text is never sent to a server, stored, or used to train any AI — it never leaves your device. When you’re ready to do more with your writing, Humanit’s AI humanizer and AI detector are one click away.
| Case | Example |
|---|---|
| Sentence case | The quick brown fox. |
| lowercase | the quick brown fox. |
| UPPERCASE | THE QUICK BROWN FOX. |
| Title Case | The Quick Brown Fox |
| camelCase | theQuickBrownFox |
| snake_case | the_quick_brown_fox |
Frequently asked questions
How do I convert uppercase to lowercase?
Paste your text, click “lowercase,” and every letter is lowercased instantly. Then use the Copy button to grab the result.
What is the difference between Title Case and Capitalized Case?
Title Case capitalizes major words but leaves small words like “a”, “of”, and “the” lowercase; Capitalized Case capitalizes the first letter of every word.
Does it support camelCase and snake_case?
Yes — it converts your text to camelCase, snake_case, and kebab-case as well as the standard writing cases, which is useful for code and slugs.
Which words should be capitalised in Title Case?
It depends on the style guide. AP and APA capitalise every word of four letters or more, so "With" is capitalised. Chicago and MLA go by part of speech and lowercase prepositions regardless of length, so "with" stays lowercase. This tool uses the four-letter convention; adjust prepositions by hand if you are writing to Chicago or MLA.
Can it restore names after I convert ALL CAPS to sentence case?
No — and no tool can. Uppercasing destroys the information that distinguishes "Brown" the surname from "brown" the colour, so it cannot be recovered from the text alone. Sentence case will fix your sentence starts; expect to re-capitalise names, places, and months yourself.
Should I use kebab-case or snake_case for URLs?
Kebab-case, with hyphens. Search engines treat hyphens as word separators and historically did not treat underscores the same way, so "ai-text-rewriter" is read as three words while "ai_text_rewriter" risks being read as one.
Is my text private?
Yes. The converter runs entirely in your browser, so your text is never uploaded or stored anywhere.
Do I need an account?
No. There’s no sign-up and no install — open the page and start typing.
Does it work on mobile?
Yes — it works in any modern browser on phone, tablet, or desktop.
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Open the AI HumanizerLast updated: May 2026