Klaviyo vs Omnisend: Which One Should Your Store Actually Be On?

This comparison gets written a lot by people who have only ever used one of the two. We run both. Most of the results on this site were built in Klaviyo, and one of the case studies, a supplement brand that went from 23.3% to 36.2% of store revenue, is an Omnisend account.

So the short answer first: for the majority of 7 and 8 figure stores, the platform is not what is holding the account back. We have taken over accounts on both tools that were producing under 20% of revenue, and the reason was never the software. It was that the list was being treated as one audience and the automation layer stopped at the first email.

That said, they are genuinely different products, and there are situations where one clearly fits better. Here is what actually separates them.

What actually differs between them

Both tools do the same core job: they sit on top of your store data, listen for customer behaviour, and let you send email and SMS based on it. Both have a native Shopify app, both connect to WooCommerce and BigCommerce, and both handle the standard automations every store needs.

The differences show up at the edges. Klaviyo has a deeper data model, which matters once you want to segment on things like predicted lifetime value, time between orders, or a custom property your store pushes in. Omnisend has a simpler builder that most teams get productive in faster, and it treats email, SMS and web push as equal citizens in the same workflow rather than bolting SMS on beside it.

Neither of those is a small difference, but which one matters to you depends entirely on where your account currently is.

Pricing, and how it changes as you scale

Both price on the number of contacts you store and send to, so your bill follows your list size. At small list sizes the gap is not meaningful. As the list grows, Omnisend is generally the cheaper of the two at an equivalent contact count, and the gap widens rather than closes.

There is a trap in this that has nothing to do with which tool you pick. You pay for contacts whether or not they ever open anything. A list carrying two years of people who have never engaged is costing you money every month and dragging your sending reputation down at the same time. On more than one account, the first thing we have done is suppress the dead weight, and the platform bill dropped while revenue went up, because the remaining list started landing in inboxes again.

So if you are choosing on price, clean the list first and then compare. Most brands are comparing quotes for a list that is 30% larger than it should be.

Segmentation depth

This is where Klaviyo pulls ahead, and it is also the thing that most decides whether an account gets to 30 or 40 percent of revenue.

On one account we took email from 25.16% to 39.07% of total revenue. Attributed revenue went from $383,309 to $822,942 a month. Almost none of that came from sending more. It came from splitting the list by purchase history, engagement recency, product affinity and value tier, so that people received fewer messages that were more relevant to them.

Omnisend can segment perfectly well for most stores. If your catalogue is straightforward and your customers buy in reasonably predictable patterns, you will not hit its ceiling. If you sell across several categories with very different repeat cycles, or you want to branch on custom data your store calculates, Klaviyo gives you more room.

SMS and running more than one channel

Omnisend has a real advantage here. Email, SMS and push share the same contact record and the same automation builder, so you can lead with email, wait, and escalate to SMS only for the people who did not engage, all governed by one set of rules.

Klaviyo also does SMS well, and running both channels inside one platform is the point either way. The failure mode to avoid is using separate vendors for email and SMS, which is how a customer ends up receiving an email and a text about the same promotion within an hour of each other. Coordination is the whole value, and you only get it when both channels read from the same suppression logic.

Used carelessly, having all three channels in one builder makes it very easy to hit the same person three times in an afternoon. The suppression rules matter more than the sending.

Migration, and when it is not worth it

Migrating between the two is normal work and we do it in both directions. The part that decides whether it goes well is sending reputation. Moving to a new platform without warming properly, and without moving your engaged segments first, is how brands land in the promotions tab and stay there for a quarter.

Done carefully, a migration is also a good moment to fix the account structure problems that were limiting the old setup, because you are rebuilding the automation logic anyway rather than importing a broken copy of it.

But be honest about the reason. If you are moving because your current tool feels limiting, check first whether you have actually hit its limits. In most accounts we audit, the flows stop at one email, the list is segmented three ways, and half the platform is unused. Changing tools rebuilds all of that from scratch on a new bill without addressing why it was never built in the first place.

So which one

If you are starting fresh, want SMS running properly without a second vendor, and your catalogue is not unusually complex, Omnisend is a strong and cheaper choice. The supplement account that went from 23.3% to 36.2% of store revenue, with monthly email revenue moving from €97,355 to €237,949, runs on it.

If your data is complex, you want deep segmentation and granular reporting, or you are already established on Klaviyo and it is set up properly, stay where you are and put the effort into the flow and segment layers instead.

And if your account is currently well under 20% of revenue, the platform is not your problem. Fix the segmentation and the automation layer first. Whichever tool you are on will look dramatically better afterwards.