Title Case, Sentence Case, or UPPERCASE: When to Use Each
Three versions of the same heading can look equally tidy and still be wrong for the document they sit in. A report may need sentence case, a journal article may need title case, and a warning label may need capitals. The choice is a convention, not a matter of taste.
The Case Converter switches text between sentence case, lower case and upper case in the browser. Knowing which one to choose takes a little more thought than pressing the button.
Quick answer
Use sentence case for running text and most web headings, title case for titles and headings under a style guide that requires it, and uppercase only for short labels, acronyms or warnings. Follow the guide your reader expects, and apply it consistently.
Sentence case: the default for prose
In sentence case, the first word and proper nouns are capitalised; everything else is lower case. It is the normal style for body text, and it is increasingly common for headings on websites and in reports because it is easy to read and hard to get wrong.
British publishing tends to favour sentence case for headings. So do many government and academic style guides. If your document has no stated rule, sentence case is the safest default.
Title case: for titles under a rule
Title case capitalises the first word, the last word and the important words in between. Short words such as “and”, “of”, “the” and “in” usually stay lower case unless they begin or end the title. But the details differ between guides: Chicago and MLA agree on the broad principle but treat hyphenated compounds and some short words differently.
Pick the guide named by your course or publisher and apply its list. Do not mix two guides in one document. A reference list that uses APA capitalisation but Chicago punctuation looks careless even when each entry is individually defensible.
UPPERCASE and lower case: two special cases
Capitals slow reading because words lose their shape. They work for short labels, acronyms, section markers and warnings where the eye needs to stop. They work badly for whole paragraphs, email subject lines and anything longer than a few words.
Long runs of capitals are harder to scan, and some screen readers handle them poorly. If everything is emphasised, nothing is.
At the other end of the scale, lower case is the right choice for code, file names, URLs, email addresses and tags where case is meaningful. Do not “tidy” these into title case. A path that changes case may stop working, and a hashtag that changes case may point somewhere else.
Small decisions that cause most errors
- Proper nouns and brand names: keep the spelling the owner uses, even if it breaks the rule.
- Job titles: capitalise when they directly precede a name (“Prime Minister Smith”), lower case when used generically (“the prime minister”).
- Hyphenated headings: check the style guide rather than guessing both halves.
- Acronyms: keep them in capitals, but do not turn a whole heading into one.
Run the text through the Case Converter, then check the exceptions by eye; the tool applies a rule, not a house style. Clean up any doubled spaces left behind with the Punctuation Fixer, and if the text is a list that needs sorting, the Alphabetical Order Tool can handle that next.
Common questions
Should headings be in sentence case or title case?
Sentence case is the safest default, especially for websites, reports and British publishing. Use title case when a style guide, course or publisher requires it, and apply the same guide throughout the document. Do not mix two guides, because their rules for short words and hyphenated compounds differ.
When should I use all capitals?
Use capitals for short labels, acronyms, section markers and warnings where the eye needs to stop. Avoid them for whole paragraphs, email subject lines and anything longer than a few words. Long runs of capitals are harder to scan, and some screen readers handle them poorly. If everything is emphasised, nothing is.
Why should file names and URLs stay in lower case?
Lower case is the right choice where case carries meaning, such as code, file names, URLs, email addresses and tags. Changing the case of a path may stop it working, and changing a hashtag may point it somewhere else. Leave these alone rather than tidying them into title case.