AI subject-line tester/optimizer
Klaviyo (AI subject lines + A/B)
Best for: Ecommerce senders wanting AI subject lines + A/B testing without a paid plan
Where it fits in content creation work
Generate 5-10 AI subject line variants per campaign and A/B test 2 variants with automatic winner selection -- on the free plan
The essentials
Starting priceFree (250 contacts) / $20/mo (Email)
Free tierA/B testing available on free plan (rare among competitors)
RegionWest