Cold Email Subject Line Analyzer
Paste a subject line and get an instant analysis: spam trigger word detection, length score, personalization check, capitalization audit, reading level, and A/B test variant suggestions. Scored 0–100.
0/200 characters · Press Enter to analyze
Great subject line — but even perfect subject lines go to spam if your email infrastructure has reputation issues. coldBirds monitors your deliverability every 6 hours and auto-suspends degraded mailboxes before your domain tanks.
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