TestSubject
Mobile email subject line and sender name preview simulator
pricingfree tierapichecked 22 Aug 2026
What TestSubject is
TestSubject by ZURB simulates how email subject lines, sender names, and preheader preview text appear across popular mobile devices including iPhones, Android devices, and modern tablet email clients. It prevents awkward text truncation, ensuring key marketing value propositions and urgency hooks remain completely visible to mobile subscribers.
Pricing
| Plan | Price | Annual | What you get |
|---|---|---|---|
| Community Tool | Free | — | Unlimited mobile inbox preview simulations across all popular mobile screen sizes |
Completely free utility for digital email marketing teams.
Free access: 100% free web utility with no registration required
read from the vendor pricing page · 22 Aug 2026 · how we verify
Best for
- Email designers checking mobile subject line line breaks and truncation
- Marketing teams ensuring sender names fit mobile inbox displays
Not for
- Automated algorithmic ad budget bidding
Integrations
TestSubject alternatives
All 4 alternatives to TestSubject, compared Get the Toolvern badge for TestSubject
SendCheckIt 16-point email subject line tester and deliverability grader 
SubjectLine.com Email subject line rating tool and AI copy optimization assistant 
Touchstone Predictive email subject line testing and open rate simulation engine 
Phrasee AI subject line optimization and language generation for enterprise email marketing Head to head: TestSubject vs SendCheckIt TestSubject vs SubjectLine.com TestSubject vs Touchstone TestSubject vs Phrasee
Compiled by Stepan Noianov from the vendor's own site and pricing page. Something wrong? Report an inaccuracy.