email subject line scorer
ai
shashank · with ai as his sidekick
7 min read · updated apr 29, 2026
paste your subject line and get an instant open-rate score — power words, spam triggers, length, sentiment, and more.
paste your subject line and get an instant open-rate score — power words, spam triggers, length, sentiment, and more.
hold your voice analyzes your full content for voice consistency — not just the subject line. keep every email sounding unmistakably like you.
start for $1six components: power words (25 pts), spam triggers (–20 pts penalty), length (20 pts), sentiment (15 pts), personalization (20 pts), and numbers/specificity (20 pts). capped at 100.
under 60 characters for desktop, under 40 for mobile-first lists. shorter lines often outperform — readers decide in under a second.
words like "free", "guaranteed", "act now", "click here", and excessive punctuation (!!!, $$$) are common triggers. this tool flags them so you can swap them out.
yes — subject lines with "you" or "your" average 6–10% higher open rates in a/b tests. first-name personalization adds another 5–15%.
founder of hold your voice. writes about brand voice, ai writing patterns, and the craft of sounding like yourself.
co-written with ai as sidekick. shashank drafts the voice; the ai pressure-tests the structure. anything that sounds wrong is shashank's fault — anything that sounds suspiciously generic is the ai's.