Building real things, in public
Notes from DEMHA FUTURE — how we build apps fast with AI, and what we learn.
Email Metrics Calculator — free online
Work out your open rate, click rate, CTOR, bounce and unsubscribe rate online for free, right in your browser, nothing uploaded.
Cold Email Rate Calculator — free online
Work out your open, reply and positive-reply rates and see how they stack up against benchmarks — free online, right in your browser, nothing uploaded.
Email Preheader Counter — free online tool
Count your email preview text live and see where each inbox cuts it off — free and online, right in your browser, nothing uploaded.
Email Signature Generator — free online
Make a clean email signature in your browser and copy it into Gmail. Free online tool, nothing is uploaded.
Email Spam-Word Checker — free online
Check your email for spam-trigger words and a risk score online, free — right in your browser, nothing uploaded.
Email Subject A/B Tester — free online
Compare email subject lines side by side and spot spam words and emoji issues, free and online, right in your browser with nothing uploaded.
Email Subject Line Counter — free online
Count the characters and words in your email subject line and see where Gmail and Outlook cut it off. Free, online, right in your browser, nothing uploaded.
Email Subject Line Scorer — free online
Score your email subject line for length, spam signals, and emojis right in your browser. Free and online, nothing uploaded.
Email Subject Line Tester — free online
Check your email subject line for length, spam words, emoji and ALL-CAPS, free and online — right in your browser, nothing uploaded.
AI Email & Letter Writer — online
Write an email, reply, cover letter or note with AI online — pick your language and tone, get a ready draft you can copy and send.
Get new posts
Soon you'll be able to drop your email and get new posts — no account, no spam.
Email sign-up isn't live yet — nothing is collected for now.