UtilibyWritten by the Utiliby editorial team · Last updated October 17, 2026 · Rules and formulas reviewed October 2026
What this free text case converter does
Capital letters matter more than most people expect. A heading in the wrong case looks careless, an all-caps email reads as shouting, and a variable name in the wrong style can break code or fail a linter. This free online text case converter fixes all of it in one place. Paste your text, press a button and get UPPER CASE, lower case, sentence case, Capitalise Each Word, four title case styles and nine programming and URL formats.
It goes further than the usual one-box converters. The title case styles follow the rules of AP, APA, Chicago and MLA. Acronyms and mixed-case brand names can be protected. A highlighted strip shows exactly which characters changed. An all-styles tab lists every result at once with a copy button on each card, and a rules tab explains how the style guides differ. You can also clean extra spaces, join lines, strip accents for code and use Turkish or Azerbaijani letter rules.
Everything runs in your browser, so your text is never uploaded.
How to convert text case
- Paste or type your text in the box, or press Try a sample.
- Choose a style from the buttons. The converted text appears below immediately.
- Set the options. Keep acronyms, protect brand names, tidy spaces, join lines or choose a language rule.
- Check the highlighted strip to see which characters changed.
- Copy, download or print the converted text, or press Use result as input to chain another conversion.
- Open the All styles tab to compare every result and copy the one you want.
Everyday cases: upper, lower, sentence and capitalised
UPPER CASE turns every letter into a capital, useful for warnings, short labels and legal headings. lower case removes all capitals, which helps when normalising data, comparing strings or fixing text typed with caps lock on.
Sentence case capitalises the first letter of each sentence and the pronoun I, and lowercases the rest. It is the best fix for text that arrived in all capitals. The tool understands that a full stop after a number is not a sentence end and starts a new capital after each new line. Proper nouns are not detected, so names such as London need a quick manual edit.
Capitalise Each Word makes the first letter of every word a capital, including small words such as of and the. It is a quick format for names, product lists and labels, but it is not correct title case for headlines.
Title case: AP, APA, Chicago and MLA
Title case is harder than it looks, because style guides disagree about which small words stay lowercase. This tool applies the main rules of each guide.
| Style | Lowercase | Capitalised |
|---|---|---|
| AP | Articles, short conjunctions, prepositions of three letters or fewer | First and last word, longer words |
| APA | Articles, short conjunctions and prepositions under four letters | Words of four letters or more, first word after a colon |
| Chicago | Articles, coordinating conjunctions and every preposition | First and last word, first word after a colon |
| MLA | Articles, coordinating conjunctions, prepositions, to | First and last word, first word after a colon |
In every style the first and last words are capitalised, as is the first word after a colon. Hyphenated words are handled part by part. The tool follows the usual rules but cannot know every exception, so check an important heading against the guide your publisher or school requires.
Programming cases: camelCase, snake_case, kebab-case and more
| Style | Example | Common use |
|---|---|---|
| camelCase | userAccountName | JavaScript, Java, Swift variables |
| PascalCase | UserAccountName | Class and component names |
| snake_case | user_account_name | Python, Ruby, database columns |
| CONSTANT_CASE | USER_ACCOUNT_NAME | Constants and environment variables |
| kebab-case | user-account-name | URLs, CSS classes, file names |
| Train-Case | User-Account-Name | HTTP header names |
| dot.case | user.account.name | Config keys, package names |
| path/case | user/account/name | Folder and route paths |
The tool splits your text into words at spaces, punctuation and existing camelCase boundaries, so converting userAccountName to snake_case works as you would expect. The accent option turns letters such as é into e, which many compilers and file systems prefer.
URL slugs
A slug is the readable part of a web address, such as /text-case-converter/. A good slug is short, lowercase, uses hyphens between words and avoids accents, symbols and filler words. The URL slug style does the mechanical part for you: it lowercases text, removes accents and punctuation and joins the words with hyphens. Trim the result by hand to the few words that matter, because short slugs are easier to read and share.
Alternating and inverse case
aLtErNaTiNg cAsE switches between lowercase and uppercase on every letter and is mostly used for tone in social posts. iNVERSE cASE flips each letter, so capitals become lowercase and lowercase become capitals. Inverse case can also repair text typed with caps lock on, where every shift press produces the opposite of what was intended.
Protecting acronyms and brand names
The most common problem with automatic case conversion is damage to words that must keep their spelling. NASA must not become Nasa and iPhone must not become Iphone. The tool offers two protections. Keep all-caps acronyms leaves words that are entirely capitals alone. Keep mixed-case brands leaves words with an internal capital letter or digit alone in title case. Both are enabled by default. Words that only look ordinary in lowercase, such as a product name typed in lowercase, cannot be detected, so proofread names after converting.
Turkish and Azerbaijani letters
In English, i and I are the same letter in two cases. Turkish and Azerbaijani have both a dotted and a dotless i, so the capital of i is the dotted İ and the lowercase of I is the dotless ı. Applying English rules produces wrong text, a long-standing source of bugs in software. Choose the language rule if you convert upper or lower case text in either language and the result will follow local convention.
Cleaning spaces and line breaks
Text copied from PDFs, emails and websites often arrives with repeated spaces, trailing spaces and odd blank lines. The tidy option collapses repeated spaces, trims line ends and reduces blank lines to one. Join lines removes line breaks and replaces them with a single space, which is useful for text copied from a column or a hard-wrapped email. Both options are applied before the case conversion.
Tips for cleaner text
- Fix all-caps text with sentence case, then correct names by hand.
- Use title case only for headings, and use the same style throughout a document.
- Prefer sentence case for interface text and subheadings. It is easier to read.
- Convert variable names with the programming styles instead of retyping.
- Check the highlighted strip if you worry that the tool changed too much.
- Chain conversions with Use result as input.
Common mistakes
- Using capitalise each word for headlines. It capitalises small words that style guides keep lowercase.
- Mixing title styles. Pick one style for the whole document.
- Converting names. Case tools cannot know whether a word is a proper noun.
- Typing long text in all capitals. It is slower to read and often seen as shouting.
- Ignoring accents in code. Strip them where the platform requires plain letters.
Limits and privacy
Conversions follow simple, documented rules. They do not understand meaning, so they cannot recognise every proper noun, brand or exception. The title case styles are simplified versions of published rules. Your text is processed in your browser and is not uploaded or stored.
Related free tools
Use these free online tools together with this one:
- Count the words and characters of your converted text with the word counter.
- See exactly what changed between two versions with the text compare tool.
- Proofread the result with the grammar and style checker.
- Make placeholder text to test cases with the lorem ipsum generator.
- Format references in title or sentence case with the citation generator.
- Style text for social posts with the bold and italic text generator.
- Score your title case headlines with the headline analyzer.
- Write the title and description for your page with the meta tag generator.
- Tidy up code after renaming identifiers with the code unminifier.
Frequently asked questions
What is a text case converter?
A text case converter changes the capitalisation of text. It can make text uppercase, lowercase, sentence case or title case, and convert it to programming styles such as camelCase and snake_case.
How do I change the case of text online?
Paste your text, then choose a style. The converted text appears straight away and you can copy it, download it or print it.
What is the difference between sentence case and title case?
Sentence case capitalises only the first word of each sentence and proper nouns, as in normal writing. Title case capitalises the main words of a heading or title, and the rules depend on the style guide.
Which title case style should I use?
Use the style your publisher, school or employer requires. AP is common in journalism, APA in social science papers, Chicago in books and the humanities, and MLA in language and literature courses.
How do the title case styles differ?
Mainly in which short words stay lowercase. AP and APA capitalise longer prepositions such as with and from, while Chicago and MLA lowercase every preposition. APA also capitalises words of four letters or more.
Does it keep acronyms such as NASA in capitals?
Yes, when the option to keep all-caps acronyms is on. Words already written in capitals are left alone in title case, capitalise-each-word and sentence case.
What happens to brand names like iPhone or eBay?
With the mixed-case option on, words that already contain an internal capital letter or digit are left unchanged in title case, so iPhone stays iPhone. Proper nouns in other words may still need a manual check.
What is camelCase, PascalCase and snake_case?
They are naming conventions used in programming. camelCase starts lowercase and capitalises each later word, PascalCase capitalises every word, and snake_case joins lowercase words with underscores.
What is kebab-case and where is it used?
kebab-case joins lowercase words with hyphens. It is common in URLs, CSS class names and file names.
Can I create a URL slug?
Yes. The URL slug style lowercases the text, removes accents and punctuation and joins words with hyphens, which suits page addresses.
What is alternating case and inverse case?
Alternating case switches between lowercase and uppercase on every letter, which is used for jokes and emphasis. Inverse case flips each letter, turning capitals into lowercase and the reverse.
Why is there a Turkish and Azerbaijani option?
In these languages the letter i has a dotted and a dotless form, so uppercase i becomes a dotted capital and I becomes a dotless lowercase. The language option applies these rules to upper and lower case.
Can it clean up extra spaces and line breaks?
Yes. Tick the cleaning option to collapse repeated spaces and blank lines, or join lines to make a single line.
Does it keep my paragraphs and line breaks?
Yes. Line breaks are kept unless you choose to join lines. Programming styles are applied to each line separately.
How do I print or save only the converted text?
Use the print or save button. The printout has the original and converted text only, not the page layout or the article. You can also copy the result or download it as a text file.
Is my text uploaded or stored?
No. The conversion runs in your browser and nothing is sent to a server or saved.
Is this case converter free?
Yes. It is free to use online with no sign-up and no limit.
Sources and further reading
- Associated Press, AP Stylebook.
- American Psychological Association, Title case capitalization.
- University of Chicago Press, The Chicago Manual of Style Online.
- Modern Language Association, MLA Style Center: Capitalizing titles.
- Unicode Consortium, The Unicode Standard: case mappings.
Sources were consulted in October 2026. Standards and rules can change, so always check the official page for your situation.