Go beyond the basics with the Klaviyo marketing app. Klaviyo syncs Shopify data in milliseconds so every message and insight reflects what’s happening in your store right now. Unify data from 350+ integrations and boost marketing performance with campaigns, smart segmentation, and automated workflows from Klaviyo’s AI Agents. Over 117k brands use Klaviyo and Shopify to grow faster with personalized emails, SMS, WhatsApp messages, and marketing automation tools that turn browsers into buyers.

Hundreds of millions of back in stock alerts and notifications delivered reliably across 25,000+ brands. Don't let out of stock products drive customers away. Pre-sell and preorder collections before they drop, and auto-notify shoppers the moment items are back in stock via email, SMS, and push. Replace "Out of Stock" with customizable "Notify Me" and preorder buttons that match your brand, device, and language. Built for high SKU volumes and fast-moving catalogs to boost cash flow fast!