By the Tooliday Team. Last updated 14 November 2026.
Capital letters look like a small detail until a heading is shouted in all caps or a file name will not work because of a space. Different places expect different case styles. This guide explains the common ones, where each is used, and how to avoid easy mistakes. You can try every style on your own text with our Case Converter.
Case styles for writing
| Style | Example | Typical use |
|---|---|---|
| UPPER CASE | SALE ENDS TODAY | Short warnings, labels, acronyms |
| lower case | sale ends today | Informal text, email addresses, tags |
| Title Case | The Sale Ends Today | Headlines, book and article titles |
| Sentence case | The sale ends today | Normal sentences, many modern headings |
Title Case versus Sentence case
In Title Case, the main words start with a capital letter, while short words such as “a”, “and”, “of” and “the” usually stay small unless they begin or end the title. Style guides do not agree on every word. Some capitalise any word of four or more letters, while others keep short prepositions lower case whatever their length. If a publisher or teacher gives you a style guide, follow it.
Sentence case capitalises only the first word and proper names, so “How to calculate a loan EMI” is Sentence case. Many websites now prefer it for headings because it is easier to read, but both are correct if you stay consistent within one page or document.
Case styles for programming and web addresses
Names in code and web addresses cannot contain spaces, so these styles join words together in different ways.
- camelCase: “totalPrice”. Common for variable and function names in JavaScript and Java.
- snake_case: “total_price”. Common in Python and in database column names.
- kebab-case: “total-price”. Common for web addresses and CSS class names.
Another style, PascalCase (“TotalPrice”), is like camelCase but also capitalises the first word. It is often used for class names. Languages and teams have their own conventions, so match the existing code around you.
A worked example
Take the phrase “monthly loan payment”. In each style it becomes:
- Title Case: Monthly Loan Payment
- camelCase: monthlyLoanPayment
- snake_case: monthly_loan_payment
- kebab-case: monthly-loan-payment
Common mistakes
- Using all caps for long text. It is harder to read and can feel like shouting.
- Mixing styles in one heading list. Pick Title Case or Sentence case and keep it consistent.
- Changing names and brands. Automatic conversion can turn “iPhone” into “Iphone” or “NASA” into “Nasa”, so check these by hand.
- Using capital letters in web addresses. Some servers treat them as different pages, so lower case with hyphens is the safest choice.
Try it yourself
Paste a heading or a phrase into the Case Converter and try each style. It runs in your browser, so your text is not sent anywhere. To check how long your text is, use the Character Counter.