Check and compare headlines, hooks, and subject lines
check_headlinesCheck headlines, email subject lines, ad openings, video hooks, social post openings and first lines, and compare options against each other. For each line it tells you whether the line does its job in that spot, meaning which of the nine reader questions it answers, and whether a competitor could send it unchanged. It also shows exactly what a reader sees before the cutoff, flags anything that fails outright, and brings in evidence from thousands of real headline tests. Then it tells you what each option is betting on and which two to test. Before you call it, list the reader questions each line answers and quote the exact words doing the work. Use it whenever you write headlines, hooks or subject lines, whenever you have to choose between them, and whenever someone asks "which one is best?" You won't get a score out of ten. Nobody can predict a winner from the words alone, and that includes this tool.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| slot | Yes | Where the lines will appear: email_subject, ad_opening, landing_page_headline, first_line, video_hook, social_post_open, sales_letter_headline. Each spot has its own job, and the check tells you what it is. | |
| brief | No | The brief. The swap test needs it to tell whether a competitor could send the line unchanged, and without it no line can pass. | |
| lines | Yes | ||
| follows | No | What the reader saw just before this line, like the ad before a landing page headline, or the headline or subject before a first line. | |
| awareness_level | No | How much the reader already knows, on Eugene Schwartz's scale. Use unaware if they don't know they have the problem, problem_aware if they feel it, solution_aware if they know solutions exist, product_aware if they know you, and most_aware if they're ready and only need the offer. |