Change the letter case of any text in one click

Content last reviewed:2026-09-30

Paste your text and pick one of five modes: UPPERCASE, lowercase, Sentence case, Title Case or Invert case. Title Case follows the APA rules for minor words, and Sentence case keeps acronyms such as NASA and capitalizes the pronoun I.

Paste or type text

Result

What is letter case?

Letter case is the difference between capital letters, also called uppercase letters or majuscules, and small letters, called lowercase. English needs capitals to start a sentence and for the pronoun I[1].

Capitals also mark proper nouns. In English these include personal names, nationalities and languages, days of the week, months, public holidays and place names[2]. Seasons stay lowercase, so you write Monday and July, but summer[1].

Titles and headings follow one of two styles. In title case, major words are capitalized and most minor words stay lowercase. In sentence case, most major and minor words are lowercase, and proper nouns always keep their capital[3].

Wooden letterpress type with capital letters, small letters and digits — Wooden letterpress type with capital and small letters. The digits among them have only one form, so the tool changes letters only and leaves digits and punctuation as they are. Photo: Amador Loureiro, Unsplash.

How do you change the case of text?

Paste your text into the Paste or type text field and click one of the five buttons above it. The result appears straight away in the Result field, and Copy result puts it on your clipboard.

UPPERCASE turns every letter into a capital, and lowercase turns every letter into a small one. Sentence case capitalizes the first word of each sentence and each line and lowercases the rest. Title Case capitalizes every word except the minor words defined by APA Style. Invert case swaps capitals and small letters.

Sentence case knows English abbreviations. It starts no new sentence after e.g. or Dr., leaves 3.5 and arteontools.com intact, and capitalizes the pronoun I, days of the week and months. Spaces and line breaks stay in place.

Caps Lock key with its light on, next to the A key — A Caps Lock key with its light on. If you type “hELLO, jOHN” with Caps Lock left on by accident, the **Invert case** mode turns it into “Hello, John”. Photo: Mika H. Laybourn, Unsplash.

Which words stay lowercase in title case?

APA Style lowercases only minor words of three letters or fewer. These are the short conjunctions and, as, but, for, if, nor, or, so and yet, the articles a, an and the, and short prepositions such as at, by, in, of, off, on, per, to, up and via[3]. Every word of four letters or more gets a capital, so With, Between and From are capitalized.

A minor word still gets a capital when it opens the title, a subtitle or the text after a colon or an em dash. Both parts of a hyphenated major word are capitalized as well, which gives Self-Report[3]. Title Case in this tool applies these rules, so the NASA report: what i learned in paris becomes The NASA Report: What I Learned in Paris.

APA uses title case for the titles of articles and books mentioned in a text, for headings and for the names of periodicals, such as Journal of Latinx Psychology or Chicago Tribune[3]. For a sentence-style title, use Sentence case and add the capitals of proper nouns by hand.

What does each mode do with the same sentence?

Every row starts from the same input: the NASA report: what i learned in paris.

Mode	Result
UPPERCASE	THE NASA REPORT: WHAT I LEARNED IN PARIS
lowercase	the nasa report: what i learned in paris
Sentence case	The NASA report: what I learned in paris
Title Case	The NASA Report: What I Learned in Paris
Invert case	THE nasa REPORT: WHAT I LEARNED IN PARIS

Results come from the tool above. Sentence case capitalizes the pronoun I, but it cannot know that paris is a city, so place names need a manual capital.

How do APA title case examples come out of the tool?

Titles taken from the APA Style guidance on title case, typed in lowercase.

Title	Kind	Mode	Result
Train Your Mind for Peak Performance: A Science-Based Approach for Achieving Your Goals	book	Title Case	Train Your Mind for Peak Performance: A Science-Based Approach for Achieving Your Goals
Turning Frowns (and Smiles) Upside Down: A Multilevel Examination of Surface Acting Positive and Negative Emotions on Well-Being	article	Title Case	Turning Frowns (and Smiles) Upside Down: A Multilevel Examination of Surface Acting Positive and Negative Emotions on Well-Being
Journal of Latinx Psychology	periodical	Title Case	Journal of Latinx Psychology
Chicago Tribune	newspaper	Title Case	Chicago Tribune

The titles and the style come from APA Style[3]. The last column is the result from the tool above.

How is Title Case different from the PROPER function in Excel?

The same input in Excel and in this tool.

Input	PROPER in Excel	Title Case
this is a TITLE	This Is A Title	This Is a Title
2-way street	2-Way Street	2-Way Street
76BudGet	76Budget	76BudGet
don't stop	Don'T Stop	Don't Stop

The Excel column follows the rule in Microsoft’s documentation[4]: a capital for the first letter and for any letter that follows a character other than a letter. The tool keeps a word with a capital inside, such as 76BudGet, as it is.

What text does this tool accept, and what does it do with it?

The tool accepts and rewrites every one of these texts, so nothing needs cleaning up before you paste. The table shows what it does with each one, and it produced the results itself.

What you type	Mode	Result	How we write it
it costs 3.5 dollars. then we left	Sentence case	It costs 3.5 dollars. Then we left	A dot inside a number is not read as the end of a sentence
visit arteontools.com today	Sentence case	Visit arteontools.com today	A web address keeps its own spelling, so the link still works
see e.g. the table. dr. smith agreed	Sentence case	See e.g. the table. Dr. smith agreed	After “e.g.” and “Dr.” we do not start a new sentence, because both are on the English list of abbreviations
i think i'm right, see you on monday	Sentence case	I think I'm right, see you on Monday	The pronoun I and the days of the week always keep their capital
The EU And NATO Signed It	Sentence case	The EU and NATO signed it	Acronyms of two to four letters keep their capitals, so UK and NASA do not turn into ordinary words
WARNING: WET FLOOR	Sentence case	Warning: wet floor	A line in all capitals is lowercased first, and only then does the sentence get its capital
20th century fox	Title Case	20th Century Fox	A letter that follows a digit stays lowercase, as in 3rd and 1980s
o'brien and d'angelo don't care	Title Case	O'Brien and D'Angelo Don't Care	A surname takes a second capital after the apostrophe, while a contraction does not
self-report	Title Case	Self-Report	Both parts of a hyphenated major word take a capital in title case
the reign of henry VIII	Title Case	The Reign of Henry VIII	A Roman numeral keeps its capitals, even in a line typed in capitals
version 2.0 is out	UPPERCASE	VERSION 2.0 IS OUT	Digits and the dot have no case, so we leave them exactly as they are

All results come from the tool. It finds the end of a sentence the same way as the word and character counter, but without relying on the case of the text, since that is often what needs fixing.

How do you change letter case in three steps?

The conversion runs in your browser, so your text stays on your device.

1. Paste your text
Type or paste your text into the Paste or type text field. It can be one sentence, a heading or a whole document.
2. Choose a mode
Click one of the five buttons above the field. The result appears straight away and updates with every click.
3. Copy the result
Copy result puts the text on your clipboard, and Clear empties the text field.

How do you change case in Word and Excel?

In Word, select the text and go to Home, then Change Case[5]. The list offers Sentence case, lowercase, UPPERCASE, Capitalize Each Word and tOGGLE cASE.

A keyboard shortcut is quicker. Select the text and press Shift + F3 until you see the case you want, or fn + Shift + F3 on a Mac. Word for the web doesn’t support changing case, while PowerPoint for the web does[5]. In Word for the web, paste the text here and copy the result back.

Excel has three text functions for this: UPPER, LOWER and PROPER[4]. PROPER capitalizes the first letter and any letter that follows a character other than a letter. That is why it turns don't into Don'T, and why it also capitalizes minor words such as of and the.

Which letters and words get special treatment?

In Sentence case, the pronoun I and its short forms I'm, I've, I'll and I'd always get a capital. So do the days of the week and the months. March, May and August are the exception, because they can also be a verb or an adjective in the middle of a sentence.

Acronyms of two to four letters, such as EU, NASA or PDF, keep their capitals in Sentence case and Title Case when they stand in a normal sentence. A longer word in capitals is usually emphasis, so the tool writes it as an ordinary word. A line written entirely in capitals is lowercased first, and names with a capital inside, such as iPhone or eBay, stay unchanged.

Roman numerals, such as VIII in Henry VIII, keep their capitals. In longer text pasted from a PDF, where lines break in the middle of a sentence, the line that continues the sentence stays in lowercase.

German text with the letter ß gets the capital ẞ in UPPERCASE mode. Since 2024, the official German spelling rules list ẞ first and allow SS as an alternative[6]. A choice between ẞ, as in STRAẞE and SS, as in STRASSE then appears below the mode buttons.

To see how many characters your text has after the change, open the word and character counter. A page title and description for search results can be checked in the meta title and description length checker, the reading time of a text in the reading time calculator, and sample text for a heading comes from the Lorem Ipsum generator.

Sources

Capital letters and apostrophes — British Council, LearnEnglish
Punctuation — Cambridge Dictionary, English Grammar Today
Title case capitalization — APA Style
PROPER function — Microsoft Support
Change the capitalization or case of text — Microsoft Support
Amtliches Regelwerk der deutschen Rechtschreibung 2024, § 25 E3 — Council for German Orthography

The results in the tables were computed by this tool's own function and checked by an automated test before publication. The rules, standards and figures the text relies on come from the sources listed above.

Content last reviewed: September 30, 2026 · written and checked by the Arteon team

Frequently asked questions about changing letter case

How do I convert uppercase text to lowercase?

Paste the text into the Paste or type text field and click lowercase. The whole text becomes lowercase, and the line breaks stay where they were.

What is the difference between title case and sentence case?

In title case, major words and every word of four letters or more are capitalized, while short minor words such as of and the stay lowercase. In sentence case, only the first word and proper nouns are capitalized.

Which words stay lowercase in APA title case?

Minor words of three letters or fewer: and, as, but, for, if, nor, or, so, yet, a, an, the, and short prepositions such as at, by, in, of, off, on, per, to, up and via. They are capitalized when they start the title, a subtitle or the text after a colon.

Does Sentence case capitalize the pronoun I?

Yes. Sentence case writes I, I'm, I've, I'll and I'd with a capital, together with the days of the week and most months. Names of people and places need a manual capital.

What is the keyboard shortcut to change case in Word?

Select the text and press Shift + F3 until you see the case you want. On a Mac, press fn + Shift + F3. Word for the web doesn’t support changing case.

Why does PROPER in Excel give Don'T?

PROPER capitalizes every letter that follows a character other than a letter, and the apostrophe is such a character. Title Case in this tool leaves contractions like don't with one capital.