The short answer
Klaviyo is built for ecommerce. If you run a Shopify store and want segmentation wired to every order, browse, and cart event, it is hard to beat. Mailchimp is the friendlier all-rounder for small businesses, newsletters, and teams that just want to send good email without learning a data platform. Both are strong. Both also bill the same way, by the size of your list, which is where the real cost story lives.
Pricing: you pay for contacts, not sends
Klaviyo and Mailchimp both charge by contact count. At around 10,000 contacts, Klaviyo's email plan runs about $150 a month and Mailchimp Standard about $135. The catch is what happens as your list grows: Klaviyo can pass $700 a month at 50,000 contacts, and Mailchimp counts unsubscribed contacts toward your bill unless you archive them by hand. You can send the same number of emails next year and still pay more, simply because more people signed up.
Where Klaviyo wins
- Deep ecommerce data: native Shopify, BigCommerce, and WooCommerce events power segmentation other tools cannot match without custom work.
- Predictive analytics, including lifetime value, churn risk, and next order date, included on paid plans.
- The widest AI feature set in the category, from generated campaigns to per-recipient send time.
Where Mailchimp wins
- A gentler learning curve and the most beginner-friendly builder in the category.
- The deepest integration library, more than 300 native connections.
- Content AI tools that are genuinely usable for non-designers.
The honest split: Klaviyo if ecommerce data is your engine, Mailchimp if simplicity is. Both make you pay for list size, not for what you send.
What neither does well
Neither shows you a real deliverability score before you send, so you learn an email landed in spam after the fact. Neither runs your marketing and your transactional email, the receipts and password resets, on one system: Mailchimp's transactional is a separate add-on called Mandrill, and Klaviyo's is a side feature. And neither is built for running several brands from one account, so agencies end up paying for a separate login per client.
A third option worth a look: SmartMailing
SmartMailing was built around the gaps both leave open. It bills by emails sent, not by contacts, so growing your list does not grow your bill. It runs promotional and transactional email on one AWS SES stack under the same brand, shows a per-brand deliverability score before you hit send, and manages multiple brands natively from one account. The starting point is different too: paste your website and the AI builder extracts your logo, colors, and fonts and assembles an on-brand email in seconds, instead of handing you a blank canvas.
If you are leaving either tool over price scaling, or you want marketing and transactional in one place, you can import your Mailchimp or Klaviyo lists in a click and see it on your own brand for free.