Title Case vs. Sentence Case: When Each One Actually Matters

Title Case capitalizes the first letter of most words in a phrase; Sentence case capitalizes only the first word (and proper nouns). Both are correct in different contexts, and mixing them inconsistently within the same piece of content is one of the more common small polish issues in published writing.

Where Title Case is the convention

Headlines, book and movie titles, and navigation labels traditionally use Title Case — it's a visual signal that a phrase is a title or label rather than a full sentence. Style guides differ on whether to capitalize short connecting words like "a," "the," or "of," which is why two publications can format the same headline slightly differently and both be internally consistent.

Where Sentence case has become the norm

Interface design and a growing share of web content has shifted toward Sentence case for headings and buttons — "Save your changes" instead of "Save Your Changes." It reads as less formal and less shouty, which is why many product interfaces and blogs default to it even in places that would have used Title Case a decade ago.

The practical rule

Match the convention of the surrounding content rather than picking per-heading. A site that uses Sentence case for its navigation and buttons but Title Case for blog post headlines will read as inconsistent even if each individual choice is defensible on its own — pick one convention per content type and apply it uniformly.