Best marketing automation platforms (Klaviyo, Omnisend, Customer.io, ActiveCampaign, Mailchimp, Braze)

The fork: storefront or product event

The category splits by where the data comes from. Klaviyo, Omnisend, and Mailchimp are built around a storefront: orders, carts, and revenue sync from Shopify or WooCommerce into the messaging engine. Customer.io is built around your product: what a user did in the app decides what lands in their inbox. ActiveCampaign plays both sides with a deep visual builder and a light CRM, and Braze runs cross-channel at enterprise scale from any data source. Choose by where your triggers live, because pricing models follow the same split (contacts for storefront tools, profiles for product tools, monthly active users for Braze).

The channel ladder

Channels are where these platforms differ most, and where marketing pages blur. Web push is genuinely built in on Omnisend (every plan, 500 a month free) and absent outright on Mailchimp and ActiveCampaign. SMS is native on Klaviyo, Omnisend, Braze, and Customer.io, and a paid add-on on Mailchimp and ActiveCampaign. Check the table rows rather than the headlines, because “omnichannel” on a vendor page sometimes means a third-party integration.

Where the money hides

Contact-based pricing is the trap in this category. Mailchimp’s send limit is a multiple of your contact count (12x on Standard), so a list cleanup changes your bill twice. Omnisend bills subscribers and non-subscribers who receive automated messages, and unsubscribed contacts are not billed, a rule worth reading twice. Customer.io keeps seats unlimited but starts at $100/mo for 5,000 profiles, and Klaviyo’s calculator quietly becomes “talk to sales” past 150,000. Model your list at next year’s size, not today’s.

Original data

We benchmark AI-crawler access across these six vendors: who blocks GPTBot, ClaudeBot, or Google-Extended, who ships an /llms.txt, and how fast the pages respond. Methodology and limitations are on the benchmark page. It matters because a platform that blocks answer engines is choosing not to be quoted, and that choice shapes which tools LLMs recommend when an operator asks for a Klaviyo alternative.

What we did not test

We have not benchmarked email deliverability, real campaign revenue performance, or migration effort between platforms, which are the tests buyers actually feel. Until we run them, those claims stay out of our tables, and the numbers shown are the vendors’ own dated pages.

Where the boundary with notification infrastructure sits

Novu, Knock, MagicBell, and Courier appear in the same integration marketplaces and get compared with this group, so the line is worth stating. Notification infrastructure delivers the message a product event creates and its job is to be useful: a deploy finished, an approval arrived, an incident started. Lifecycle messaging exists to change what the person does next, which is why segmentation, campaign analytics, and revenue attribution live here and not there. Customer.io is the closest to the line, triggering from product events exactly like Novu, but its surfaces are marketing-owned (email, SMS, push campaigns) rather than the in-app inbox and product chat surfaces. The notification-infrastructure comparison links from this page when both decisions are open at once.