Klaviyo and Omnisend are both purpose-built for e-commerce email — but Klaviyo is the market leader with deeper data integration and more sophisticated segmentation, while Omnisend bundles email, SMS, and web push at lower entry price. For stores spending $1M+ and optimizing email revenue attribution, Klaviyo’s data depth is worth the premium. For stores starting out that want email + SMS in one place at lower cost, Omnisend is the more accessible choice.

Omnisend is cheaper at most contact tiers. Klaviyo’s free plan is more restrictive (250 contacts vs Omnisend’s 250 contacts with 500 sends, but Klaviyo allows unlimited sends on paid tiers).

Klaviyo’s Shopify integration is the deepest available — it surfaces product views, time since last purchase, predictive lifetime value, and expected next order date in its segmentation engine. You can segment customers who viewed a specific product category 3+ times in the last 30 days but haven’t purchased in 60 days. Omnisend covers the standard e-commerce segments but lacks some of the granular behavioral signals Klaviyo surfaces.

Omnisend includes web push notifications alongside email and SMS — Klaviyo does not. For stores that want to reach visitors across three channels from one platform, Omnisend’s breadth is an advantage. The automation builder coordinates email, SMS, and push in the same flow.

Omnisend is generally the right choice for stores under $500K GMV where budget is a constraint and multi-channel breadth is valued. Klaviyo is the right choice for stores that have proven email as a revenue channel and want to optimize it with deeper data. The switching point is often when stores are spending enough on email that the attribution precision Klaviyo provides is worth the premium.

Klaviyo’s flow builder is more powerful than Omnisend’s in every measurable way — conditional splits, time-delay branching, and predictive analytics triggers give enterprise stores surgical control over customer journeys. Omnisend’s automation templates are friendlier to set up and cover the core use cases like abandoned cart and welcome sequences, but the logic ceiling is noticeably lower. When a store needs to branch flows based on lifetime value tiers, product category affinity, or predictive churn scores, Omnisend simply doesn’t have the native tooling to compete. Klaviyo wins this dimension decisively, and for stores where email automation drives a meaningful share of revenue, that gap compounds over time.