You're writing the title for a blog post, the subject line for a newsletter, or the H1 on a new landing page. Should it be How to Cook the Perfect Egg, or How to cook the perfect egg? Both are grammatically correct. Both are widely used. But they signal different things, and choosing the wrong one for the context is one of those small things that makes copy look slightly off without the reader knowing why.

This guide walks through both styles, when to use each, and how a few small decisions about capitalization can quietly improve the polish of your writing.

What title case actually is

Title case capitalizes the major words in a heading: nouns, verbs, adjectives, adverbs, and pronouns. Small connecting words — articles like a, an, the, coordinating conjunctions like and, but, or, and short prepositions like at, by, in, of, on, to — usually stay lowercase. The first word and last word are always capitalized regardless of which category they fall into.

So you'd write The Lord of the Rings, not The Lord Of The Rings. You'd write Of Mice and Men with both the first Of capitalized (because it's the first word) and the and lowercased.

The complication is that "title case" isn't one set of rules. There are at least eight major style guides, and they disagree about details. AP style lowercases prepositions of three or fewer letters; Chicago style lowercases all prepositions regardless of length; APA style capitalizes any word of four or more letters even if it's a preposition. We'll come back to these differences.

What sentence case actually is

Sentence case treats a heading the way you'd treat a regular sentence. The first word is capitalized. Proper nouns — names of people, places, brands, books — are capitalized. Everything else is lowercase.

So the sentence-case version of The Lord of the Rings would be The lord of the rings. The sentence-case version of How to Cook the Perfect Egg would be How to cook the perfect egg.

One catch: proper nouns stay capitalized even in sentence case. A visit to Paris keeps Paris capitalized. Apple's quarterly results keeps Apple capitalized. Sentence case doesn't make everything lowercase — it follows the same rules as the body of a paragraph.

When title case is the right choice

Title case has been the default for English titles for a few centuries. It signals formality, permanence, and self-contained authorship — the things you'd associate with a published work. Use it for:

  • Book titles, song titles, movie titles, album titles. To Kill a Mockingbird. Bohemian Rhapsody. The Shawshank Redemption. These are works that should look like distinct objects, and title case is how English typography signals that.
  • Newspaper and magazine headlines, in publications that follow AP, NY Times, or similar journalism style guides. President Signs New Climate Bill. Markets Rally as Inflation Cools.
  • Section headings inside formal documents — academic papers (under most style guides), legal briefs, technical white papers, annual reports.
  • Marketing copy that wants to feel established. A press release, an investor announcement, a corporate blog post on a topic that needs to sound authoritative. Title case adds gravitas.
  • Email subject lines for transactional or formal contexts — order confirmations, official notices, legal updates.

When sentence case is the right choice

Sentence case has become the default for digital writing over the last decade, especially in tech. It signals conversation, immediacy, and approachability — the things you'd associate with someone talking to you rather than publishing at you. Use it for:

  • UI text and product copy. Button labels, error messages, modal headings, navigation items. Sentence case feels modern and friendly. Create new project reads better in a sidebar than Create New Project.
  • Microcopy on websites and apps — tooltips, form labels, settings descriptions.
  • Marketing copy that wants to feel personal. The hero text on a SaaS landing page. The headline on a Mailchimp template. Most of what tech companies write today is in sentence case.
  • Email subject lines for casual or personal contexts — newsletter blasts where the brand voice is informal, transactional emails from younger consumer brands.
  • Most documentation — Stripe, GitHub, Notion, and most modern developer docs use sentence case for headings.

The cultural shift

Twenty years ago, almost all professional writing used title case for headings. Today, sentence case has become standard in tech, design, and most digital products. If you visit The New York Times, the headlines are still in title case. If you visit Apple's website, almost everything is in sentence case. If you visit Stripe's docs, every heading is in sentence case. The split correlates closely with how recently the brand was built and how much it positions itself as conversational.

There's no objective winner — but if you're picking a default for a new project today and you're not sure, sentence case is the safer modern choice. It's harder to get wrong (no style-guide arguments about which prepositions to capitalize), and it reads as contemporary. Title case still has its place; it's just no longer the only option.

Mixing the two consistently

Whichever you choose, the rule is: be consistent within a section. A blog post with sentence-case headings and one stray title-case heading looks like a mistake. A product with title-case page titles and sentence-case button labels is fine because they're different categories of text and your readers will subconsciously expect the distinction.

Common patterns that work:

  • Page H1: title case. All sub-headings (H2, H3, H4): sentence case. Body: sentence case. Buttons: sentence case.
  • Page H1: sentence case. All sub-headings: sentence case. Body: sentence case. Buttons: sentence case.
  • Page H1: title case. All sub-headings: title case. Body: sentence case. Buttons: title case. (More formal feel — common in legal, academic, corporate.)

Edge cases worth knowing

Hyphenated words in title case are handled differently by each style guide. AP and Chicago capitalize both parts: Mid-Atlantic, State-of-the-Art. APA capitalizes both parts. Wikipedia generally capitalizes only the first: Mid-atlantic. Our style-guide converter handles each correctly.

Words after a colon are usually capitalized regardless of word type in title case — and even in sentence case, if the words after the colon form a complete sentence. The Truth: It's Not What You Think.

Brand names with non-standard capitalization stay in their canonical form. iPhone, eBay, GraphQL, PostgreSQL, JavaScript stay exactly as written even in the middle of a sentence-case or title-case heading. Don't "fix" them. Our case converter has a built-in 5,000-name dictionary that preserves these correctly.

Acronyms stay uppercase: NASA, FBI, USB. Don't apply title-case logic to them.

Quotations within a title: usually keep the quoted text in whatever case it was originally. The Real Meaning of "Be Kind" uses sentence case inside the quotes even though the surrounding title is title case.

A practical decision tree

If you're stuck on a single piece of text right now and need to decide:

  1. Does your organization have a style guide? Use what it says.
  2. Is this a published work title (book, song, movie)? Title case.
  3. Is this a newspaper-style headline? Title case (AP or your publication's style).
  4. Is this an academic paper title? Title case (whichever style the journal requires).
  5. Is this UI text, marketing copy, documentation, or social-media content? Sentence case is the modern default.
  6. Is this a casual context where the brand voice is informal? Sentence case.
  7. Still unsure? Sentence case. It's harder to get wrong.

Try it on your own text

The fastest way to internalize the difference is to paste a few of your existing headings into our case converter, switch between Title Case and Sentence case, and see which one matches the voice of your brand. With explain mode on, you can also see exactly which rule fired on each word — useful for understanding why one style guide capitalized a word and another didn't.

It's the kind of thing that feels invisible when you get it right, and unprofessional when you get it wrong. A few minutes of attention pays off across every page you publish.