Klaviyo vs Mailerflow: Ecommerce Depth or AI-Built Email?

Klaviyo vs Mailerflow comes down to what you want the platform to do first. Klaviyo is built around ecommerce data — profiles, purchase history, revenue attribution — while Mailerflow is built around AI that drafts your emails and automations, with unlimited sending on every paid plan. If your roadmap is "attribute more revenue to email and segment on purchase behaviour," Klaviyo is the natural starting point. If your roadmap is "send more, build faster, and stop paying per send," Mailerflow is the one to look at.

Everything below separates verified facts (checked 2026-10-23 on the official pricing pages named in each section) from judgment calls. Where a competitor detail isn't verified, this article says so and points you to the official page rather than guessing.

Comparison table (verified 2026-10-23 on official pricing pages)

Verified 2026-10-23 on klaviyo.com/pricing and mailerflow.ai pricing.

Klaviyo's free plan also includes built-in reporting, email support, web forms, mobile app marketing, revenue attribution for campaigns, engagement and click-through rates, ticket management, Klaviyo Academy courses and the Klaviyo Community. That is a genuinely generous free tier for a small store that wants to see revenue attribution before committing.

Not sure your current tool is the right fit? Compare the Best Email Marketing Platforms by price, features and free plans for your exact list size.

Pricing and plan limits: what you actually pay for

Two different pricing philosophies

Klaviyo's free plan is verified at 250 profiles and 500 emails per month. Paid tiers and their limits change over time, so model your own numbers on klaviyo.com/pricing rather than trusting a blog post — including this one.

Mailerflow's structure is simpler to forecast: a Free plan with 2,500 contacts and 10,000 emails a month, paid plans from $14.90/month, and unlimited emails on every paid plan. Yearly billing costs the same as 10 months.

A worked example (illustrative)

Say you have 12,000 contacts and send four campaigns a month. That's 48,000 emails monthly.

On a send-capped plan, that volume is the thing you're buying — you'd need a tier whose monthly send allowance covers 48,000 plus your automations, and you'd re-check the tier every time your list or cadence grows. On Mailerflow, 12,000 contacts fits the Growth plan at $29.90/month, and the 48,000 sends don't change the price because sending is unlimited.

That's not an argument that one model is better. It's an argument that you should calculate your own send volume first, then compare. If you send rarely to a small list, a capped plan can be cheaper. If you send often, or your automations generate a lot of one-to-one volume, unlimited sending removes a variable from your budget.

Email editor and templates: manual control vs describing what you want

Klaviyo's free plan includes an AI-powered subject line generator, verified 2026-10-23. Beyond that, the editor and template feature set is best checked in Klaviyo's official docs — it has evolved, and this article won't invent detail it can't verify.

Mailerflow's AI email builder works differently: you describe the email you want and get a complete responsive design back, along with subject lines and preview text. There's also a visual block editor (headings, heroes, products, columns, social links) and reusable templates when you'd rather assemble it yourself.

The practical split: if you have a designer who wants pixel-level control over every block, a traditional drag-and-drop editor is the right tool. If you're a small team with no designer and a long list of emails to produce, describing the email and editing the result is faster. Either way, run a human pass over brand voice, links and legal footers — AI output is a first draft, not a final one.

Automation: ecommerce flows vs AI-drafted workflows

Klaviyo's automation is oriented around ecommerce — browse, cart, post-purchase, win-back. For the current list of flow types and limits, go to Klaviyo's official documentation rather than a comparison post.

Mailerflow uses visual automations with waits, conditions, webhooks and AI steps, triggered by signups, events, dates, inactivity and website behaviour. The AI automation builder takes a sentence and drafts the workflow — trigger, waits, conditions, emails — for you to review before it goes live. Plan limits on active automations are 3 on Free, 10 on Starter, 50 on Growth, and unlimited on Pro and above.

A concrete example: an abandoned-browse flow that triggers when a contact views a product page, waits one day, checks whether a purchase happened, and only then sends the follow-up email. You could describe that in one sentence and review the draft. The AI gets you to a working skeleton quickly; deciding what the email should say, and how long the wait should be, is still your job.

Segmentation and personalization

Klaviyo's free plan includes basic customer segmentation and revenue attribution for campaigns, verified 2026-10-23. Its strength is tying segments to purchase and revenue data — that's the core of the product, and it's why ecommerce teams choose it.

Mailerflow builds dynamic segments on fields, tags, engagement, events and website behaviour, and can generate a segment from a plain-language description. AI personalization steps and website-behaviour data via the JS SDK let you tailor emails to what each contact actually read or did.

The foundation is the same for both: clean contact data. Mailerflow's CSV import checks for duplicates and invalid addresses, and custom fields and tags are what make segmentation work later. If you're weighing other ecommerce-first tools too, this Omnisend vs Mailerflow comparison covers a similar trade-off from a different angle.

Deliverability and sending infrastructure

Mailerflow sends from your own domain with guided DKIM, SPF and DMARC setup and automatic verification. Bounces and complaints are suppressed automatically, reputation is monitored, and warm-up limits apply to new domains. Analytics cover delivery, bounces, complaints, clicks and approximate opens, per campaign and overall.

Klaviyo publishes its own deliverability documentation; this article won't claim infrastructure details that aren't verified. What's true for both platforms is the checklist that actually moves the needle:

1. Authenticate your sending domain (SPF, DKIM, DMARC) before your first campaign.
2. Warm up a new domain gradually instead of blasting your full list on day one.
3. Watch bounce and complaint rates weekly, not quarterly.
4. Suppress or re-engage non-openers before they drag your reputation down.
5. Keep transactional and marketing sending separated where your setup allows it.

Transactional email, API and integrations

Mailerflow offers a transactional email API on a high-priority lane with templates and variables, plus a REST API with scoped keys, idempotency keys, an OpenAPI spec, code samples and a JS SDK. Signed real-time webhooks include retries and delivery logs.

For Klaviyo's transactional and API specifics, go to Klaviyo's developer documentation — the free plan's verified inclusions (web forms, mobile app marketing, ticket management) don't tell you what the API supports today.

The decision here is architectural. If you want order confirmations, password resets and marketing email in one place with one contact record, that shapes your choice. If your engineering team already owns transactional email and you only need campaign tooling, the API matters less. Teams building lifecycle email for a SaaS product often land on a different shortlist entirely — see Loops vs Mailerflow for that comparison.

Support, data location and compliance

Klaviyo's free plan includes email support, Klaviyo Academy courses and the Klaviyo Community, verified 2026-10-23. The same pricing page notes email support for the first 60 days on the Marketing tier — worth reading carefully if support response time matters to you.

Mailerflow provides GDPR tools: data export, erasure, consent logs and configurable retention, with data hosted in Europe. Embeddable signup forms support double opt-in and keep consent records. Free migration help covers contacts, suppression lists, templates and core automations on eligible paid plans.

If EU data residency is a requirement from your legal team, that's a concrete differentiator. If it isn't, weigh migration effort instead: moving a large list with years of engagement history is real work, and free migration help shortens it.

Which one to choose for teams comparing email platforms beyond the biggest names

Choose Klaviyo if you sell online, revenue attribution and purchase-data segmentation drive your roadmap, and you want an established ecommerce ecosystem with a free plan (250 profiles, 500 emails/month) to test the model before paying.

Choose Mailerflow if you want AI to draft emails and automations, unlimited sending on paid plans, a lower entry price, EU data hosting, and migration help moving off your current tool. Start with the feature overview and check plan limits against your list size.

Consider both if you run ecommerce but your list is large and send volume is your main cost driver. In that case, price your actual monthly sends on Klaviyo's official pricing page, then compare against Mailerflow's unlimited-send tiers. If you're also evaluating newsletter-first tools, Beehiiv vs Mailerflow and this roundup of HubSpot email marketing alternatives cover adjacent ground.

FAQ

Is Klaviyo free?

Yes. Klaviyo offers a free plan with 250 profiles and 500 emails per month, verified 2026-10-23 on klaviyo.com/pricing.

Does Mailerflow have a free plan?

Yes — 2,500 contacts and 10,000 emails a month, with 3 active automations and 100 AI actions per month.

Can I send unlimited emails on Mailerflow?

Yes, on every paid plan. The Free plan is capped at 10,000 emails a month.

Can I migrate my contacts and templates?

Mailerflow offers free migration help with contacts, suppression lists, templates and core automations on eligible paid plans. For Klaviyo, check their official documentation for import options.

Which is better for ecommerce?

It depends on whether revenue attribution or AI-built sending matters more to your team. Klaviyo is designed around purchase data; Mailerflow is designed around fast production and unlimited sending. Both can run ecommerce campaigns.

Where is my data stored?

Mailerflow hosts data in Europe. For Klaviyo's data locations, check their official documentation.

Try Mailerflow on the Free plan (2,500 contacts, 10,000 emails a month, AI automation builder included), import your contacts by CSV, and ask about free migration help on eligible paid plans. See Mailerflow pricing.