Best Email Marketing for Shopify 2026: Klaviyo vs Postscript vs Omnisend Compared

Klaviyo is the best email marketing platform for most Shopify stores in 2026 — its deep Shopify data integration, segmentation capabilities, and predictive analytics make it the highest-ROI platform for stores doing $100K+ in annual revenue. Postscript is the best SMS marketing tool for Shopify — if SMS is your channel of focus (average 98% open rates vs email's 20-40%), Postscript's Shopify-native SMS flows outperform Klaviyo's SMS add-on for specialized use cases. Omnisend is the best budget option for smaller stores — its email + SMS combined plan at $16/month handles both channels at a lower cost than Klaviyo's equivalent tier. The choice depends on your revenue stage: under $50K ARR use Omnisend, $50K-500K use Klaviyo, SMS-primary brands use Postscript.