Result
It depends on the guide and on how "since" is used. As a preposition ("Lessons since Launch"), it is five letters long: AP, APA, AMA, and Bluebook capitalize it, while Chicago and MLA keep it lowercase. As a subordinating conjunction ("Since You Asked," "What Changed Since We Moved"), Chicago and MLA capitalize it too, so every guide writes "Since."
"Since" (as a Preposition) by Style Guide
| Style guide | "Since" mid-title | Why |
|---|---|---|
| AP | Capitalize | Prepositions of four or more letters are capitalized |
| APA | Capitalize | Words of four or more letters are capitalized |
| Chicago | Lowercase | Prepositions are lowercase at any length |
| MLA | Lowercase | Prepositions are lowercase at any length |
| AMA | Capitalize | Prepositions longer than three letters are capitalized |
| Bluebook | Capitalize | Prepositions longer than four letters are capitalized ("since" has five) |
The Same Headline in Four Styles
| Style | "everything we learned since launch" |
|---|---|
| AP | Everything We Learned Since Launch |
| APA | Everything We Learned Since Launch |
| Chicago | Everything We Learned since Launch |
| MLA | Everything We Learned since Launch |
The converter treats "since" as a preposition. When a clause follows ("What Changed Since We Moved"), capitalize it in Chicago and MLA as well.
Related Words
"After" and "before" follow the same two-part rule.
"Since" in Sentence Case
APA reference lists, many news sites, and most UI text use sentence case instead of title case. There, only the first word and proper nouns get capitals, so "since" is lowercase unless it starts the title: "Everything we learned since launch." Pick one of the two styles for a whole set of headings rather than mixing them.
Quick Answers
Should "since" be capitalized in a title?
In AP, APA, AMA, and Bluebook, yes. In Chicago and MLA, only when it starts a clause.
Is "since" capitalized in APA?
Yes. APA capitalizes words of four letters or more.