For ecommerce brands and marketers looking to scale with advanced automation and personalization, Klaviyo has emerged as a go-to email and SMS marketing platform. But if you’re currently using Mailchimp, Omnisend, or another provider, you’re likely wondering: How easy is it to migrate to Klaviyo, without losing data, momentum, or your mind?

The good news? Klaviyo makes migration surprisingly straightforward, offering built-in tools, guides, and even migration support for new users. In this article, we’ll walk through how the migration process works, what you need to prepare, and how the transition compares depending on your current platform.

Why Migrate to Klaviyo?

Before we dive into the “how,” let’s quickly touch on the “why.”
Klaviyo is purpose-built for ecommerce, with powerful features like:

• Deep integrations with Shopify, WooCommerce, BigCommerce, etc.

• Real-time behavioral and transactional data sync

• Dynamic segmentation

• Multi-channel automations (email + SMS)

• Robust A/B testing and predictive analytics

If your current tool feels limiting in terms of data visibility or automation, a move to Klaviyo can open up major performance gains.

Migration Overview: How It Works

No matter where you’re coming from (Mailchimp, Omnisend, Constant Contact, ActiveCampaig) the core steps are the same:

1. Create a Klaviyo account

2. Connect your ecommerce platform

3. Import your contacts and lists

4. Migrate email templates

5. Rebuild automations (flows)

6. Set up consent settings (GDPR, TCPA)

7. Test everything before going live

Let’s look at how this applies to the most common migration scenarios:

Migrating to Klaviyo from Mailchimp

Difficulty: ⭐⭐☆☆☆ (Easy)
Tools Available: Klaviyo has a native Mailchimp integration for seamless migration.

✅ What Transfers Automatically:

• Email lists and tags

• Contact data (names, emails, engagement metrics)

• Campaigns (as static records)

• Custom properties (via .CSV or API)

• Opt-in status

🚫 What Needs Manual Work:

• Automations (flows): you’ll need to rebuild in Klaviyo

• Templates: Mailchimp templates need to be manually recreated or imported as HTML

• Reports: campaign performance won’t transfer over

Pro tip: Klaviyo has a dedicated Mailchimp migration guide and customer support to walk you through the process.

Migrating to Klaviyo from Omnisend 

Difficulty: ⭐⭐⭐☆☆ (Moderate)
Tools Available: No native integration, but CSV exports and manual setup are straightforward.

What You Can Transfer:

• Contact lists and segments (via CSV)

• Tags and custom properties

• SMS opt-ins (must be clearly marked)

• Historical campaign data (manually via export)

Manual Setup Required:

• Automations: Flows in Omnisend don’t transfer; you'll need to rebuild them in Klaviyo

• Templates: HTML can be imported, but blocks may not carry over

• Signup forms: Must be rebuilt using Klaviyo’s form builder or embedded manually

Pro tip: Klaviyo’s segment-based logic is more advanced than Omnisend’s—take the opportunity to improve your targeting.

 

Migrating from Other Tools (e.g., ActiveCampaign, Constant Contact, Sendinblue)

Difficulty: ⭐⭐⭐☆☆ (Moderate to Easy)
Approach: All use CSV exports and HTML/template migration.

General Process:

• Export contacts with their fields (make sure opt-in status is included)

• Export email templates or recreate in Klaviyo’s drag-and-drop editor

• Export performance reports (optional, for benchmarking)

• Rebuild core automations (e.g., welcome, cart abandonment, winback)

Ecommerce Platform Integration: The Easy Part

The first thing you should do in Klaviyo is connect your ecommerce platform—whether that’s Shopify, WooCommerce, or BigCommerce.
This syncs:

• Customer purchase history

• Site behavior (browse abandonment, product views)

• Order and revenue data

Shopify users benefit the most, as Klaviyo’s native app enables real-time sync, product catalog access, and revenue attribution without complex setup.

Bonus: If you're using Shopify and Klaviyo, the app automatically tags imported Mailchimp contacts, so you can track engagement after the switch.

Email Templates: Rebuild or Import?

You can:

• Rebuild emails in Klaviyo’s drag-and-drop editor (fastest for long-term use)

• Import HTML from your old platform

• Use Klaviyo’s template library for a fresh start

Keep in mind that design elements (like buttons, font spacing, or media blocks) might not carry over perfectly due to different rendering engines.

Automations (Flows): Start Fresh, Start Smart

This is where Klaviyo shines—and where you'll want to spend most of your migration time.

Even though flows from Mailchimp or Omnisend won’t port over directly, Klaviyo provides:

• Pre-built flows (welcome series, abandoned cart, post-purchase)

• Custom triggers and splits based on behavioral + transactional data

• Built-in SMS workflows with branching logic

Suggestion: Don’t copy-paste old flows. Use the migration as a chance to refine your timing, content, and logic.

 

Consent and Compliance: Don’t Miss This Step

During migration:

• Make sure contact opt-in status is carried over (especially for GDPR/CCPA compliance)

• Separate your SMS and email lists if needed

• Review Klaviyo’s compliance settings for signup forms and double opt-in

Klaviyo lets you apply consent profiles to contacts so you don’t accidentally send to unsubscribed users.

Testing Before Going Live

Before you hit send:

• Preview and test each email on mobile and desktop

• Send test campaigns to internal lists

• Double-check UTM tracking and reporting settings

• Enable Smart Sending to prevent fatigue

Klaviyo also allows A/B testing in both campaigns and flows—use this feature early to validate your new setup.

Final Thoughts: Is It Worth the Effort?

Yes.
While migration does take a few hours of work (or a few days for complex setups), the payoff in data accuracy, automation power, and segmentation flexibility is significant.

Klaviyo is designed to scale, and if you're serious about lifecycle marketing, switching over is an investment in long-term performance.

And the best part? Our Klaviyo specialists can guide you through the onboarding phase, documentation, and migration services.

Migration Quick Guide

Need Help Migrating to Klaviyo?

If you're ready to make the move but want expert support, many Klaviyo Partners (like us at Mediaposte Martech) offer complete migration packages: contact import, automation rebuilds, template creation, and strategy optimization, all handled for you.