Do you capitalize is in titles and headings? The short answer is yes, is needs to be capitalized because it is a verb, and verbs are always capitalized in title case.
The long answer is: Contrary to popular belief, title case does not mean that all short words are lowercased. Word length does play a role (for example, some styles lowercase prepositions with up to three letters, but capitalize all longer ones), but the word class is even more important. Only articles, conjunctions and (short) prepositions are lowercased in title case. Verbs must be capitalized, no matter how long (or short) they are, and this includes two-letter verbs like be, is, and do.
Here are a few examples of correctly capitalized titles:
This Is Us
The Price Is Right
All You Need Is Love
Santa Claus Is Comin’ to Town
If you are unsure which words to capitalize in a title, check out the Title Case Converter which will automatically capitalize your titles correctly.
Photo: Jakob Søby (edited)