How to Change Text Case: UPPER, lower, Title & camelCase
Fix text typed with Caps Lock on, or switch between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case and more, free in your browser.
Almost everyone has typed a whole paragraph and then looked up to see it all in capitals because Caps Lock was on. Other times you are handed a list of headings where some are in capitals, some are lowercase and a few are a mix. Retyping all of that is slow, and it is easy to add new typos along the way.
Developers, writers, students and office workers all need to change text case for different reasons. A blog editor needs consistent headline capitalization. A programmer needs variable names in camelCase or snake_case. A marketer building web addresses needs lowercase words joined by hyphens. This guide covers the common case formats, where each one is used, and how to convert text quickly without retyping.
What “text case” means
“Case” is about whether letters are capital (uppercase) or small (lowercase). The name comes from old print shops, where capital letters were kept in the upper case (a tray) and small letters in the lower one.
Some formats only change capitalization. Others also change the spaces between words. For example, snake_case swaps spaces for underscores, and camelCase removes spaces and uses capitals to mark where each new word begins. These joined formats exist because many systems, such as programming languages, file systems and web addresses, handle spaces badly or not at all.
The nine common case formats
The table below shows the same phrase, “monthly sales report”, in each format, along with where you will usually see it.
| Format | Example | Where it is commonly used |
|---|---|---|
| UPPERCASE | MONTHLY SALES REPORT | Warning labels, short headings, acronyms, emphasis |
| lowercase | monthly sales report | Email addresses, tags, casual writing, cleaning up data |
| Title Case | Monthly Sales Report | Headlines, book and article titles, menu items |
| Sentence case | Monthly sales report | Normal sentences, many website headings, buttons |
| camelCase | monthlySalesReport | Variable and function names in JavaScript, Java and similar languages |
| PascalCase | MonthlySalesReport | Class names, component names in many frameworks |
| snake_case | monthly_sales_report | Python variables, database column names, some file names |
| kebab-case | monthly-sales-report | URLs (web addresses), CSS class names, file names |
| CONSTANT_CASE | MONTHLY_SALES_REPORT | Constants and settings in code, environment variables |
For file names, kebab-case and snake_case are safe choices because they avoid spaces, which some programs and websites turn into odd characters like %20. For URLs, lowercase kebab-case is the usual choice because it is easy to read and works the same everywhere.
Title Case vs Sentence case
These two are the ones people mix up most often.
Title Case capitalizes the first letter of most words: “How to Change the Case of Your Text”. Sentence case capitalizes only the first word and any proper nouns, just like a normal sentence: “How to change the case of your text”.
Neither one is “correct”. It depends on the style your organization, publication or website follows. Title Case can feel more formal and traditional. Sentence case tends to look calmer and is often easier to read in longer headings. The most important thing is to pick one and use it consistently across a document or site.
Small words in titles
In Title Case, most style guides keep certain short words lowercase unless they come first or last in the title. These usually include:
- Articles: a, an, the
- Short conjunctions: and, but, or, nor
- Short prepositions: of, in, on, at, to, for, by
So you would write “The Lord of the Rings”, not “The Lord Of The Rings”. Style guides disagree on the details, for example whether longer prepositions like “with” or “about” should be capitalized, so check the guide you are expected to follow when it matters.
Built-in case tools in office software
Most popular office programs offer some way to change case, but the options vary.
| Tool | What it generally offers | Limitations |
|---|---|---|
| Word processors (such as Microsoft Word) | A change case command with uppercase, lowercase, sentence case and capitalize-each-word options | Usually no programming formats like snake_case or kebab-case |
| Online document editors (such as Google Docs) | A capitalization menu with uppercase, lowercase and title-style options | Limited set of formats; your text is stored in an online account |
| Spreadsheets (such as Excel or Google Sheets) | Formulas that convert cells to upper, lower or “proper” case | Requires writing formulas; no joined-word formats |
| Deftivo Case Converter | All nine formats listed above, side by side | Works on pasted text rather than inside a document’s formatting |
Office tools are handy when you are already editing a document. When you need formats for code, file names or URLs, or you just want to fix some text quickly, a dedicated converter is usually faster. Note that the “capitalize each word” option in many programs capitalizes every word, including “and” and “of”, so you may still need to lowercase small words by hand.
How to change text case with Deftivo
The Deftivo Case Converter runs entirely in your browser. Your text is processed on your own device and is never uploaded.
- Open the Case Converter page.
- Paste your text into the Your text box. All nine formats update instantly as you type.
- Find the format you need, such as Title Case, snake_case or kebab-case.
- Click Copy next to it and paste the result where you need it.
If you are cleaning up text copied from a PDF or email that has line breaks in the middle of sentences, run it through Remove Line Breaks first, then change the case. If you also need to check length, for example for a title tag or a social media post, the Word Counter shows word and character counts.
Tips and pitfalls
Check proper nouns. Automatic converters cannot know that “london” should be “London” or that “iphone” is a brand name with its own styling. After converting to lowercase or Sentence case, read through and fix names of people, places, companies and products.
Watch acronyms. Converting “NASA and the UN” to Title Case may produce “Nasa and the Un”. Converting to lowercase loses acronyms entirely. Fix these manually afterward.
Keep a copy of the original. Once text is in all lowercase, the information about which words were capitalized is gone. If the original had correct capitals for names, keep it somewhere until you have checked the result.
Be careful with code. Many programming languages are case-sensitive, meaning userName and username are two different things. Renaming a variable in one place without updating every other place will break your code.
Do not overuse UPPERCASE. Long passages in capitals are harder to read, and in emails or messages they can come across as shouting. Save it for short labels or warnings.
Mind punctuation in joined formats. When converting to snake_case or kebab-case, symbols such as apostrophes, ampersands or slashes may be removed or handled differently than you expect. Check the result, especially for URLs and file names.
FAQ
How do I fix text I typed with Caps Lock on?
Paste the text into a case converter and choose Sentence case, which capitalizes only the first letter of each sentence. Then read through it and restore capitals for names, places and acronyms, since no tool can guess those reliably.
What is the difference between camelCase and PascalCase?
Both join words without spaces and use capitals to mark each new word. In camelCase the first letter is lowercase (monthlyReport), while in PascalCase it is uppercase (MonthlyReport). Many coding conventions use camelCase for variables and PascalCase for class names.
Should I use underscores or hyphens in file names and URLs?
For URLs, hyphens (kebab-case) are the common convention because they are easy to read and widely treated as word separators. For file names, either works well as long as you are consistent. Both are better than spaces, which can cause problems in links and command-line tools.
Is my text safe when I use an online case converter?
It depends on the tool. Some online services send your text to their servers for processing. Deftivo’s converter works entirely in your browser, so the text you paste stays on your device and is not uploaded.