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Case Converter

Switch text between UPPERCASE, lowercase, Title Case, Sentence case, and aLtErNaTiNg with one click per case.

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Quick answer

Case Converter rewrites your text in any of five cases: UPPERCASE, lowercase, Title Case, Sentence case, and aLtErNaTiNg. Paste your text and click a case, and the converted version appears below for you to copy. Title Case capitalises the first letter of every word, and Sentence case capitalises the start of each sentence. The conversion runs in your browser, so your text is not uploaded.

What the Case Converter does

Retyping text just to fix its capitalisation is tedious. A heading may arrive in all caps, a sentence may be stuck in lowercase, or a title may need each word capitalised. This tool switches text between five cases in one click and leaves your original in place, so you can try another case.

Each of the five options has an everyday use. UPPERCASE is for shouting and lowercase for toning it down. Title Case capitalises every word of a heading, Sentence case fixes the start of each sentence, and alternating case gives text a playful look.

How it works

UPPERCASE and lowercase apply the standard letter-case transforms to the whole text. Alternating case walks through the characters, lowering the even positions and raising the odd ones.

Title Case capitalises the first letter of every word and lowercases the rest. Sentence case first lowercases everything, then capitalises the first letter of the text and the first letter after each sentence-ending . ! or ?.

Data source & conversion logic

  1. Step 1. Paste or type your text. It stays in your browser and is not uploaded.
  2. Step 2. Click one of the five cases: UPPERCASE, lowercase, Title Case, Sentence case, or aLtErNaTiNg.
  3. Step 3. UPPERCASE and lowercase transform the whole text, and alternating case toggles letter by letter.
  4. Step 4. Title Case capitalises the first letter of each word, and Sentence case capitalises the letter after . ! or ?.
  5. Step 5. Copy the result. Your original text stays as you pasted it.

Technical details

CasesUPPERCASE, lowercase, Title, Sentence, aLtErNaTiNg
Title CaseCapitalises the first letter of every word
Sentence caseLowercases all, then capitalises sentence starts
CasingBrowser Unicode rules (accented and non-Latin letters work)
OriginalKept; the result goes to a separate box
UploadNone. The conversion runs in your browser

Standards and references

  • Title case: Style guides capitalise major words and lowercase short articles, conjunctions, and prepositions. This tool uses a simpler rule and capitalises the first letter of every word.
  • Sentence case: Sentence case capitalises only the first word and proper nouns. This tool capitalises sentence starts, but because it lowercases everything first, it does not restore capitals on proper nouns.
  • Unicode case mapping: Upper- and lowercasing follow the browser's built-in Unicode rules, which handle accented and non-Latin letters.

Accuracy and limits

UPPERCASE, lowercase, and alternating case are exact transforms. Every letter converts predictably, and the browser's Unicode rules cover accented and non-Latin characters.

Title Case here is the simple kind: it capitalises the first letter of every word. Style guides such as AP, Chicago, and APA lowercase short words like a, of, and, and the, so a formal title may need those lowercased by hand afterwards.

Sentence case lowercases the whole text first, then capitalises the start of each sentence. That fixes shouting or all-lowercase text, but it also removes capitals from proper nouns and the word I (except where one starts a sentence), so you may need to fix names.

The tool finds sentence boundaries by looking for . ! and ?, so an abbreviation such as Dr. or e.g. can trigger an unwanted capital, and it treats a line with no end punctuation as one sentence.

Real-world uses

Fix all-caps text

Turn a heading or message that arrived in capitals into normal sentence or title case.

Make a quick title

Capitalise each word of a heading or filename in one click.

Clean up pasted text

Put text with mixed capitalisation into one consistent case.

Playful styling

Use alternating case for a meme-style or sarcastic look.

When it fits, and when it doesn't

Good for

  • Switching between the five common cases
  • Fixing all-caps or all-lowercase text
  • Quick title or sentence capitalisation
  • Text with accented and non-Latin letters

Not the best choice for

  • Strict style-guide title case (minor words stay capitalised)
  • Keeping proper nouns capitalised through sentence case
  • camelCase, snake_case, or kebab-case for code
  • Language-specific casing edge cases

For a title that follows style-guide rules, use a dedicated title-case converter. For code identifiers, use a tool built for camelCase or snake_case.

Frequently asked questions

What cases can it convert to?
Five: UPPERCASE, lowercase, Title Case (first letter of every word), Sentence case (start of each sentence), and aLtErNaTiNg case. Click a button to apply one.
Does Title Case follow style-guide rules?
Not strictly. It capitalises the first letter of every word, while AP, Chicago, and APA title case lowercase short articles, conjunctions, and prepositions like a, and, and of. For a formal title, lowercase those by hand.
Why did Sentence case lowercase a name?
Sentence case lowercases the whole text first, then capitalises sentence starts. It cannot tell a proper noun from an ordinary word, so names and the word I lose their capitals unless they begin a sentence. Capitalise those again by hand.
How does it decide where a sentence ends?
It looks for a full stop, question mark, or exclamation mark. That works for normal prose but can miscount around abbreviations and decimals.
Does it change my original text?
No. It writes the converted version to a separate box for you to copy. Your input stays as you pasted it, so you can try another case.
Does it handle accented or non-English letters?
Yes. Upper- and lowercasing use the browser's Unicode rules, so accented Latin and many non-Latin scripts convert correctly.
What is alternating case for?
It lowercases and uppercases letters in turn, giving the aLtErNaTiNg look often used for sarcasm or memes. It changes only the look of the text.
Can it do camelCase or snake_case?
No. Those are programming naming styles, not letter cases. This tool covers the five cases used in normal writing, and a developer naming-case tool handles camelCase and snake_case.
Is my text uploaded?
No. The conversion happens in your browser and the text is not sent to a server. Clearing the box removes it.
Can I convert a whole document?
Yes. Paste as much text as you like. Very large pastes depend on your device, since the conversion runs in your browser, but normal documents convert instantly.

References

This page describes the five modes the tool runs. It also explains that its Title Case capitalises every word and that its Sentence case drops capitals on proper nouns.

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Back to the Case Converter

Paste or pick your input at the top of the page. The conversion runs on this device and needs no account.

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