Whether with should be capitalized in a title or headline depends on several factors, notably, the style guide you are using and the position of with in the title. The following overview will cover the possible cases in detail.

In AP, APA, and New York Times style, with is always capitalized, because these styles capitalize all prepositions with four or more letters.

In both Chicago and MLA style, all prepositions are lowercased, independent of their length, while in Wikipedia style, all prepositions with four or fewer letters are lowercased. Therefore, with is generally lowercased in these three styles:

However, with must be capitalized if it is the first or last word of the title:

Titles and headlines do not necessarily have to be written in title case. If you are using sentence case instead, then with is generally lowercased:

The obvious exception are titles where with is the first word. In such a case, it is capitalized:

The rules for capitalizing with can be summarized as follows:

Do not capitalize with if …

• you are using sentence case and it is not the first word of the title
• you are using Chicago, MLA, or Wikipedia style title case and it is neither the first nor the last word

Capitalize with in all other cases

If you haven’t already, try out the Title Case Converter, which will automatically capitalize with correctly in your titles.