Headline and Subject Line Scorer

A free tool for checking an email subject line, page headline, search result title or Google Ads headline before it goes out. Each check says whose rule it is: a platform's published limit, a regulator's guidance, or AAJ's view. Compare up to 20 versions at once. It runs in your browser.

What it checks

• Email subject lines: Mailchimp recommends no more than 60 characters, 9 words, 3 punctuation marks and 1 emoji. A "Re:" or "Fwd:" on a first message is flagged: the FTC's CAN-SPAM guide says the subject line must accurately reflect the content of the message, and applying that to reply prefixes is AAJ's reading.
• Google Ads headlines: up to 30 characters, with a Korean, Japanese or Chinese character counting as 2. Emoji, repeated punctuation such as "!!", symbols like "*flowers*" and gimmicky capitals break Google's ad policies on punctuation and capitalisation.
• Search result titles: Google sets no length limit but shortens titles to fit the device width, and advises against vague titles such as "Home" and repeated words.
• Every kind: claims that need proof, hedges, jargon and abstract nouns, from the same word lists the aaj-copywriting agent skill uses. For factual claims, the FTC says advertisers must have evidence to back them up.

Phrases that read as spam (on subject lines), words in capitals, repeated exclamation marks and a missing number or name are AAJ's view, and each is labelled so.

Why it doesn't give you a score out of 100

Most headline graders return a number, and nobody can say what it predicts. What these checks can do is catch common problems: an ad Google's policies don't allow, a claim you can't prove, a subject line that reads as spam, a vague or repetitive title. So the tool counts checks passed and leaves "which one wins" to a test, which the A/B Test Significance Calculator can size and read.

Limits

• It can't predict clicks or opens; only a test with your audience can.
• It doesn't know your positioning. A clean line can still say the wrong thing.
• Inboxes differ. Mailchimp's numbers are a recommendation, not a cut-off.

To check every claim in a full page, use the Claims & Proof Checker. To test a headline on real people, use the Five-Second Message Test.