Eight tools to sharpen the email you're writing right now.
Subject line scoring, spam linting, CTA grading, readability, preheaders, cold email drafting, A/B prediction, and sounds-like-AI detection. Paste your draft, get a fix, ship a better email.
- No signup
- 3 runs / tool / day
- Results in <2s
- Copy-paste anywhere
Eight tools, one focus: ship better emails.
Each tool does one thing well, with a real rubric behind it — not a chat box that wants more context.
Subject Line Tester
Paste a subject line. Get a 1–100 score, a breakdown of why, and three sharper alternatives.
Email Spam Checker
Paste an email. We flag spam-trigger words, all-caps abuse, link risks, and missing unsubscribe — instantly, no AI required.
CTA Grader
Paste a CTA. Get directness, urgency, and friction scores plus five better versions.
Readability Checker
Paste an email. See its Flesch reading ease, grade level, and sentence-length distribution. No AI, just math.
Preheader Generator
Give us a subject. We'll write five preheaders that amplify it — none of them just restate it.
Cold Email Generator
Tell us the goal, audience, and offer. We'll draft a cold email that respects their time and gets a reply.
A/B Test Predictor
Drop in two variants. We predict the winner, the confidence, and which dimension decided it.
Sounds-Like-AI Detector
Paste an email. We score how human it sounds and highlight the three most AI-flavored spans.
Subject lines, scored before they ship.
Paste a subject. Get a 1–100 score, a breakdown of every factor that pushed it up or down, and three sharper alternatives — each with their own score. The rubric is open, not a black box.
- Length, word choice, specificity, curiosity gap
- Spam-trigger penalties surfaced inline
- Three alternative subjects, each scored
- Pair with preheader generator for paired-line synergy
Different sends, different stacks.
Pick the right 2-3 tools for the email you're writing. The whole workflow takes about as long as drafting it cold.
Stop sending the templates your prospect has seen 40 times. Test subjects, prove the open, write the cold email itself.
Re-engage dormant subscribers without sounding desperate. Score deliverability, sharpen the ask, prove it doesn't trip filters.
Big sends with no second chances. Predict the winner before you announce. Generate preheaders that earn the click, not the open.
Multi-touch sequences that don't fatigue. Check readability per step, audit for AI tells, keep your voice consistent across the journey.
Three steps. About two seconds.
Paste the email
Drop in your draft, subject, or CTA. Tools accept whatever fragment you have — no setup, no signup.
Get the breakdown
Scores, line-level annotations, and concrete suggestions in under two seconds.
Ship the fix
Copy the better version back into Gmail, your ESP, or our editor and send with confidence.
Six dimensions every send should pass.
The same lint your draft gets in the full app. No black box — here's everything we look at.
Spam-trigger words
~400 phrases scored by severity, not just matched.
All-caps ratio
Per-line, not just averaged — one shouty header still trips filters.
Link audit
Shorteners, suspicious TLDs, redirect chains, mismatched display URLs.
Length & rhythm
Word count, sentence histogram, paragraph density vs. your audience baseline.
CTA strength
Directness, urgency, friction — and whether the CTA matches the subject promise.
Unsubscribe path
CAN-SPAM and GDPR compliance — flagged before it goes to your ESP.
When the tools aren't enough.
Targeted fixes
- 3 runs / tool / day, no signup
- Subject, CTA, preheader scoring
- Local-only spam + readability lint
- Cold email + A/B prediction
- Copy-paste back into any ESP
"I just wanted the email to convert."
"I used to A/B test every subject by intuition. The tester catches the dumb stuff in three seconds — saves me a full Asana ticket."
"The spam checker flagged a sentence I'd been re-using in welcome emails for two years. Opened-but-never-clicked finally made sense."
"Cold-email generator gave me three takes I'd never have written. Replied prospect said the contrarian one made him stop scrolling."
Questions, answered.
Are these tools really free?+
Yes. Three runs per tool per day per IP — enough to fix the email you're writing, not enough to replace an editor. Sign up for unlimited.
Do I need to install anything?+
No. Each tool runs in the browser-adjacent layer or our API. Paste, run, copy the result.
Where does my pasted email go?+
AI-backed tools (rewrite, predict, generate) call our backend over HTTPS. We don't train on or persist your text — see Privacy. Local-only tools (spam check, readability) never leave your browser pane.
Can I use these for client work?+
Absolutely. Free tier is fine for one-offs. Sign up if you're running them daily across multiple brands — Pro pools 1,500 runs and unlocks brand-voice memory per workspace.