Ten visible checks · 175-word spam list · nothing uploaded
Will they open it? Score the line before you send.
Every check shown — length, curiosity, spam words, the exact character where Gmail cuts you off.
Try:
Score
81/100
Strong
Characters
37
sweet band 26–50
Words
8
aim for 4–8
The ten checks
- Length 37 chars — the sweet spot (mobile shows ~35, desktop ~70).
- Word count 8 words — scannable at a glance.
- Concrete number A number — specifics read as credible and get opened.
- Curiosity frame Statement only — a question frame adds pull.
- Second person Speaks to the reader directly — the strongest single lever.
- Power words No emotional trigger words — one curiosity/urgency word helps.
- Emoji No emoji — fine for B2B; one can lift B2C opens.
- Capitalization Sentence case — reads like a person, not a promo.
- Exclamations No exclamation marks — calm reads confident.
- Spam words Clean against the 175-word trigger list.
Where clients cut it off (approximate)
Gmail app (mobile)Your Q4 plan: 2 spots left this…35 ch
Outlook (desktop)Your Q4 plan: 2 spots left this month45 ch
Yahoo MailYour Q4 plan: 2 spots left this month60 ch
Apple Mail (iPhone)Your Q4 plan: 2 spots left this month65 ch
Gmail (desktop web)Your Q4 plan: 2 spots left this month70 ch
Truncation figures are engineering approximations — devices, font sizes and zoom shift them. The … marks where the line would cut.
Scoring runs entirely in your browser — nothing is uploaded. Scores grade the checklist, not your list; your own open data makes the final call.
All 7 subject line tools
free, no signupWhat this site does — and what it does not
- Every check shown — you see each point move and why.
- Nothing uploaded — all scoring stays in your browser.
- One engine everywhere — tester, generator, checker agree.
- Not an inbox-placement guarantee — reputation and engagement outrank words.
- Doesn't know your list — your open data outranks the checklist.
- Not an AI writer — deterministic templates, no black box.