Your subject line decides whether the email gets opened or buried. Paste it in, watch it score out of 100 as you type, and grab a few rewrites you can steal.
You can write the best email of your life, but if the subject line falls flat, nobody reads it. The subject is the only part most people see before they decide to open, scroll past, or send you to spam.
This scorer checks the things that actually move opens — length, spam-trigger words, curiosity, clarity, and whether it feels written for a person. Type and it grades in real time. No login, nothing saved to a server.
Type or paste a subject line. It scores instantly across six things that move open rates, flags anything risky, and hands you rewrites.
Your score updates live as you write. Aim for 70+ before you hit send.
Same idea, sharpened into proven angles. Tap to copy.
Type a subject line above and rewrites will appear here.
No magic, no black box — just the six things that decide whether your subject earns the open.
Long subjects get cut off on phones. The sweet spot lands around 20–50 characters — enough to be clear, short enough to read at a glance.
Words like "free," "act now," and rows of exclamation points can trip filters and read as salesy. We flag them so you can swap them out.
A number, a question, or an open loop gives people a reason to open instead of scroll. We check for the hooks that pull a click.
If a reader can't tell what's inside in a second, they skip it. Tight word count and clean punctuation keep it readable.
"You," "your," or a first-name merge tag makes the line feel written for one person, not blasted to a list.
SHOUTING IN CAPS, stacked punctuation, and emoji pile-ups undercut trust. A little personality is good; a circus isn't.
This is Day 31 of 120 free drops inside the Sidekick Summer Slam. One marketing or operations tool in your inbox, every single day from May 8 → September 4. Free, the whole way through.
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