Three styles, and when to use each
Headline capitalization is a style choice, not a grammar rule, which is why style guides disagree. What matters is picking one and applying it everywhere: your title tags, H1s, H2s and product copy. Mixed styles are one of the quickest ways to make a site look unedited.
- AP title case. Used in news and many marketing blogs. The rule is about length: capitalize words of four letters or more, lowercase short articles, conjunctions and prepositions. “How to Launch With No Audience”.
- Chicago title case. Used in books and long-form publishing. The rule is about the kind of word: prepositions stay lowercase however long they are. “How to Launch with No Audience”.
- Sentence case. Capitalize the first word and proper nouns only. “How to launch with no audience”. It’s the style this site uses for headings.
The tricky words
Most disagreements come down to a handful of cases, and this converter handles them like this:
- First and last word. Always capitalized in both title styles, even “A” or “To”. The first word after a colon is also capitalized.
- Verbs with a particle. In “Sign Up”, “Log In” and “Set Up”, the second word is part of the verb, not a preposition, so it’s capitalized. We detect common ones; check anything unusual.
- Hyphenated words. The first part follows the normal rules. Later parts are capitalized unless they are minor words in the middle: “Step-by-Step”, “Add-On”.
- Acronyms and brands. SEO, API and iPhone are left as you typed them. If your whole input is in capitals, we treat it as shouting and convert everything.
Use it with your other headline tools
Paste a whole list, one headline per line, to convert a batch of blog titles or H2s in one go. Then check the final title’s length and look in the SERP preview, or generate options with the AI title generator. Turning a title into a URL? The slug generator lowercases it for you.
The rules here are a summary of each style’s common rules, not the full guides. If your publication follows AP or Chicago strictly, check edge cases against the current edition.