Klaviyo vs Mailchimp: The Billing Difference That Decides It

Most comparisons of these two argue about features. That's the wrong axis, because the feature gap closed years ago and the bill didn't. Both platforms will build you an automation, segment a list, and render a drag-and-drop template. What separates them is a billing rule that neither one puts on the pricing page in plain language, and it decides which of them gets expensive as your list grows.

Here's the part worth knowing before anything else: Mailchimp charges you for contacts who unsubscribed. Klaviyo doesn't.

That sounds like a footnote. On a list of any real size it's the whole decision.

The free plans are the same offer

This surprises people who assume Klaviyo is the premium option. As of August 2026, both free tiers land in the same place:

Identical ceilings. If you're under 250 contacts, pick on interface preference, because the economics are a wash and you'll outgrow both within a few months of doing anything seriously.

The 250-contact ceiling is low on purpose. It's enough to prove the product works and not enough to run a business on.

Where the billing models split

Mailchimp prices on contacts stored in your audience. Klaviyo prices on billable profiles, which their documentation defines as active profiles that can receive at least one type of marketing. The distinction matters because of what Klaviyo excludes: suppressed and unsubscribed profiles drop out of your billable count once the suppression finishes processing, which can take up to 72 hours.

Think about what that means over two years of sending. Every list accumulates dead weight; people unsubscribe, addresses hard bounce, and contacts go stale. Under Klaviyo's model that decay stops costing you money. Under Mailchimp's, those contacts sit in your audience and keep counting toward the tier you're paying for, unless you go in and archive or delete them yourself.

Plenty of people never do that housekeeping, and the bill quietly ratchets up for an audience that can't receive mail.

There's a catch worth naming on the Klaviyo side. Their profile allowance and send volume are billed as separate constraints: your plan has to cover both your billable profile count and how much you actually send. A small, heavily-mailed list can push you into a higher tier on send volume alone, which is not obvious until it happens.

Mailchimp's published prices, and the ones they don't publish

Mailchimp does list entry prices, which is more than Klaviyo does:

• Essentials, from $13/month, covering up to 500 contacts, with sends capped at 10x your contact count (5,000)
• Standard, from $20/month, same 500-contact band, sends capped at 12x (6,000)
• Premium, from $350/month, covering up to 10,000 contacts, sends capped at 15x (150,000)

Those are entry prices for the smallest band of each tier, and the jump from Standard to Premium is the one that ambushes people. Anything above 10,000 contacts also gets a 15% discount applied, which tells you something about where their pricing pressure is.

Klaviyo publishes no equivalent table. You choose a profile count in their calculator and it returns a number. I'm not going to quote figures I can't verify against a source, and neither should any comparison article you read: third-party posts citing Klaviyo tier prices contradict each other constantly, because the tiers move and the posts don't. Run both calculators against your own contact count on the day you're deciding. That's the only number that's true.

Also worth doing before you commit: check what your bill looks like at double your current list size, not your current one. You're not buying for today.

What each one is genuinely better at

Klaviyo is an ecommerce platform that sends email, and the distinction shows. Its Shopify integration reads order history, browse behaviour, and purchase timing, then segments on all of it. If you sell products online and you want an abandoned-cart flow that knows what was in the cart and what the customer bought last time, Klaviyo is built for that and Mailchimp is approximating it. Their predictive features are trained on an enormous pool of store data, which is not something a competitor can simply decide to build.

Mailchimp is the better generalist. It's the more forgiving interface for someone who isn't technical, the template library is deeper, and it does a lot of adjacent marketing work (landing pages, social posting, a basic CRM) that Klaviyo either doesn't touch or treats as secondary. For a restaurant, a nonprofit, a consultancy, or anyone whose business isn't an online store, Mailchimp's breadth is a real advantage and Klaviyo's ecommerce depth is dead weight you're paying for.

The short version: if you have a Shopify store, the answer is usually Klaviyo. If you don't, Klaviyo's main advantage doesn't apply to you.

The switching cost people underestimate

Exporting contacts is easy. Both platforms give you a CSV in a few clicks.

What doesn't come across is everything else: your automations have to be rebuilt by hand, your templates need reworking because the block systems aren't compatible, and your sending reputation on a new platform starts from nothing. That last one is the expensive part. Move a 20,000-contact list to a new sender and blast it on day one, and you'll teach every inbox provider that an unknown sender just started high-volume mailing, which is precisely the pattern spam filters exist to catch.

Warm up over two or three weeks, starting with your most engaged segment. Whatever you save on the monthly bill, you lose several times over if you land in spam for a month.

When neither is the right answer

There's a case both platforms handle badly, and it's common: a business with a large list that sends to it infrequently.

Say you have 15,000 contacts and email them twice a month. Both platforms bill you primarily on the size of that list, so you're paying for storage you barely use. The contacts aren't the cost to the provider; the sending is. You're on the wrong side of the pricing model.

That's the gap Flomailr was built for. Pro is $19/month flat, it includes 50,000 sends, and you can store as many contacts as you want without the price moving. The free tier is 500 contacts and 5 campaigns a month, which is twice the contact ceiling of either platform above.

I'd rather be straight about where that trade lands, because it isn't free. Flomailr has no SMS, no predictive analytics trained on a decade of store data, and nothing approaching Klaviyo's depth on Shopify. If your business lives or dies on ecommerce personalization, buy Klaviyo; you'll be happier and it'll pay for itself.

What Flomailr does have is the sending safety most platforms leave to your judgment. Suppression lists, daily caps, quiet hours, and send idempotency are enforced on the server, so a mistake in a campaign or an integration can't push past them. You can check any domain's SPF and DMARC setup with our free checker before you send anything, from either platform or ours.

Deciding

Run your actual contact count through both calculators, then ask two questions.

Do you sell products online, and does your email need to know what people bought? If yes, Klaviyo, and stop reading comparisons. If no, you're deciding between Mailchimp's breadth and a cheaper flat-rate tool, and that comes down to whether you'll use the extra surface area Mailchimp gives you or just pay for it.

The one thing I'd push back on is the reflex to stay put because migrating feels like a project. Work out what your current platform will cost at 2x your list size. If that number makes you wince, the migration is worth three weeks of warming up, and it only gets more expensive to put off.

Prices and plan limits above were checked against klaviyo.com/pricing and mailchimp.com/pricing/marketing in August 2026. Both platforms change tiers without much announcement, so verify against the live calculators before you commit.