Free Public Utility
Email Subject Line Tester & Deliverability Score
68% of recipients decide whether to open or mark an email as spam based on the subject line alone. Test and optimize your hook in real time.
Overall Score
98 / 100
Excellent open potential
Length
49 chars
â Ideal (30-55 chars)
Anti-Spam Filters
0 Alerts
Clean vocabulary
Mobile Preview
Gmail & iOS
How to cut your newsletter bill by 10x in 2026 đ
Diagnostic details:
Optimized length for mobile screens
Contains numbers (+18% higher clicks)
Zero spam trigger words detected
No excessive CAPITALIZATION
AI-Suggested Subject Line Variations:
Click to copyMaximum Curiosity+28% higher opens
How to cut your newsletter bill by 10x in 2026 (What nobody is talking about)
Data-Driven Hook+22% higher opens
3 surprising metrics: How to cut your newsletter bill by 10x in 2026
Direct Benefit+35% higher opens
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