Title case vs sentence case: which should you use?

Every headline, heading and button label needs capitalising, and there are two conventions. Most organisations pick one without much deliberation, apply it inconsistently, and end up with a site where half the pages look different from the other half.

The choice itself matters less than people think. The consistency matters more.

The two conventions

Sentence case capitalises the first word and any proper nouns. That is all.

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Title case capitalises the significant words and leaves the minor ones lowercase.

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The first reads like prose. The second reads like a headline. Both are correct; they signal different things.

Which words stay lowercase in title case

This is where it gets fiddly, and where most people apply the rule inconsistently without noticing.

The general convention: capitalise everything except articles, coordinating conjunctions, and short prepositions — unless the word is first, last, or follows a colon.

Articles: a, an, the Coordinating conjunctions: and, but, or, nor, for, yet, so Short prepositions: at, by, in, of, on, to, up, via, with

So:

A Tale of Two Cities The Lord of the Rings What to Look for in a Car

Note A and The capitalised at the start despite being articles, and for lowercase in the third example despite being four letters. The first-and-last rule always wins.

Where the style guides disagree

If you have ever seen two publications capitalise the same headline differently, this is why. The disagreement is almost entirely about prepositions.

Chicago Manual of Style keeps all prepositions lowercase regardless of length. So Notes Toward a Theory of Everything — toward stays lowercase even at seven letters.

AP Stylebook capitalises prepositions of four letters or more. Same headline becomes Notes Toward a Theory of Everything — with Toward capitalised.

APA capitalises anything of four letters or more, preposition or not.

MLA is closer to Chicago, keeping prepositions lowercase.

None of these is wrong. If you are writing for a publication, follow theirs. If you are writing for yourself, pick one and stop thinking about it — the four-letter rule is the easiest to remember and apply consistently.

There is also a fourth convention that appears mostly in marketing: Capitalising Every Single Word Including The Articles. It is not standard in any major style guide, and it reads as slightly amateurish to anyone who notices. Avoid it.

When each one suits

Sentence case has become the default for user interfaces and much of the technology industry. Apple, Google and Microsoft all use it in their design guidelines for buttons, menus and labels.

The arguments for it are practical. It is faster to read, because capital letters slow scanning slightly. It is far easier to apply consistently, since there is only one rule. It handles product names, acronyms and unusual capitalisation gracefully — iPhone and eBay do not need special-casing. And it translates better, since many languages do not use title case at all and a sentence-case original converts more naturally.

Title case still dominates editorial contexts: news headlines, book titles, academic papers, formal documents. It signals that something is a title rather than a sentence, which is genuinely useful when a heading might otherwise be misread as prose.

A reasonable split, if you want a rule:

The mistakes worth avoiding

Mixing both on the same page. The most common failure. A title-case page heading with sentence-case subheadings looks like an oversight, because it usually is one.

Capitalising every word. How To Reduce Your File Size capitalises To, which no major style guide does. It is the most recognisable marker of a headline nobody edited.

Getting the first and last word wrong. a Tale of Two Cities and What Are You Looking for both break the rule. First and last are always capitalised regardless of what the word is.

Forgetting the colon rule. In title case, the word after a colon is capitalised even if it would otherwise be lowercase: War and Peace: A Novel of the War.

Applying title case to a sentence. If your heading is a complete sentence with a verb, title case often reads oddly. We Have Updated Our Privacy Policy is grammatically fine and visually strange.

Hyphenated compounds

The fiddliest corner of title case, and the one that produces the most inconsistency within a single document.

The usual convention capitalises each part of a hyphenated compound, applying the same minor-word rules within it:

State-of-the-Art Design A Well-Known Problem Twenty-First-Century Writing

Note of and the staying lowercase inside the compound, exactly as they would between separate words. Well-Known capitalises both parts because neither is a minor word.

Chicago adds an exception: do not capitalise the second part when it is a prefix that cannot stand alone, so Anti-inflammatory rather than Anti-Inflammatory. Whether that distinction is worth maintaining depends on how much of your writing involves prefixed technical terms.

If your text contains many hyphenated terms and you have no house style, sentence case sidesteps the question entirely — which is a legitimate reason to choose it.

Handling names and acronyms

Both conventions defer to the correct capitalisation of proper nouns. This trips up automated conversion in a specific way worth knowing.

Converting a headline to sentence case requires lowercasing everything first, then capitalising sentence starts. That process destroys proper nouns — The Paris Review interviews David Foster Wallace becomes The paris review interviews david foster wallace. No rule can recover them, because there is no way to distinguish paris the city from parking the activity without understanding the sentence.

This is a genuine limitation rather than a bug in any particular tool, and it is why title case is often the safer automated conversion for text containing names: capitalising every significant word gets proper nouns right by accident, leaving less to fix by hand.

The case converter here restores what can be identified reliably — the pronoun "I", and title abbreviations like Dr., Mrs. and St. — but names will need checking. Its sentence-case conversion also handles the case most converters get wrong: it recognises that "Dr. Smith arrived" is one sentence rather than two, and that the full stop in "3.5kg" is a decimal point rather than a sentence ending.

Length matters more than capitalisation

Worth putting the whole question in perspective: how a headline is capitalised affects how it looks. How long it is affects whether anyone reads it.

Search engines truncate page titles at roughly 580 pixels — not a character count, which is why two titles of identical length can cut in different places depending on how wide their letters are. Social platforms truncate at their own limits. A headline that gets cut mid-phrase loses whatever you put at the end, which is usually the part that mattered.

Aim for roughly 50–60 characters for a page title and check before publishing. The word counter shows character counts against the common platform limits as you type.

The practical recommendation

If you have no existing convention, use sentence case for interface text and either for headings, chosen once and documented somewhere your colleagues will find it.

Sentence case is easier to apply consistently, which means it stays consistent. Title case looks more traditional and more editorial. Both are defensible. What is not defensible is having both on the same site because nobody wrote the decision down.