People move from Mailchimp to Klaviyo for one reason above all others: they want email marketing built around what customers actually buy, not just who is on a list. Mailchimp treats ecommerce data as an add-on bolted onto a general marketing tool. Klaviyo treats it as the foundation — every profile is built from order history, browsing behaviour, and product-level data pulled straight from your store.
That difference changes the order you should do things in. With most migrations you export contacts first and worry about integrations later. With Klaviyo, the store connection comes first, because it is what turns a flat CSV of email addresses into profiles with purchase history, predicted lifetime value, and product affinity attached. Do the contact import before the store sync and you end up with thin profiles you have to rebuild anyway.
The rest of the migration is a genuine rebuild rather than a transfer. Segments, flows, and templates all need recreating in Klaviyo's structure. It takes longer than a like-for-like platform swap, but for a store with real purchase volume the payoff in targeting is usually why the switch was worth making in the first place.
How long this takes
4–6 hours
Most of that time goes into rebuilding automations and repointing forms, not the import itself.
Why switch from Mailchimp to Klaviyo?
Switch if…
- You run a Shopify or WooCommerce store and want segmentation built on real purchase and browsing behaviour.
- You want abandoned cart, browse abandonment, and post-purchase flows that go deeper than Mailchimp’s ecommerce templates.
- You need predicted customer lifetime value and product-level analytics tied directly to email performance.
- You want SMS and email managed from the same profile and the same flow builder.
- Your current Mailchimp automations feel shallow next to what your order volume could support.
Stay put if…
- You do not run an ecommerce store — Klaviyo is built around order and product data you may not have.
- Your customer base is large and Klaviyo’s per-profile pricing would cost noticeably more than Mailchimp at the same volume.
- You need broad general-purpose marketing features like landing pages and social scheduling that Klaviyo does not prioritise.
Mailchimp vs Klaviyo: the key differences
| What changes | Mailchimp | Klaviyo |
|---|---|---|
| Data model | List-based audiences | Profile-based, built from behaviour and orders |
| Store connection | Optional integration, bolted on | Core to the platform, connected before contacts |
| Pricing basis | Contacts stored | Active profiles, rises with store size |
| Automation | Customer journeys, general-purpose | Flows, purpose-built around ecommerce triggers |
| Segmentation | Tags and static groups | Dynamic segments from behaviour and purchase data |
| Analytics | Campaign-level reporting | Revenue attribution tied to individual flows and campaigns |
| SMS | Limited or third-party | Native, managed alongside email in the same flow |
| Onboarding curve | Simple, general marketer friendly | Steeper, assumes ecommerce context |
Before you switch, have this ready
- Admin access to your Shopify or WooCommerce store and your Mailchimp account.
- A Klaviyo account created with your store connected before you import any contacts.
- A list of every flow currently running in Mailchimp, including triggers and delays.
- Your non-store contact sources documented — anyone not tied to an order, such as newsletter-only signups.
- A test order you can place to trigger abandoned cart and post-purchase flows.
- Half a day of focused time, ideally scheduled away from a live promotion.
Step-by-step: Mailchimp to Klaviyo
Step 1: Connect your store to Klaviyo first
From Klaviyo, go to Integrations and connect your store platform. This is the single most important sequencing decision in the whole migration — Klaviyo pulls customer, order, and product data directly from the store, and profiles created this way carry purchase history from day one.
Klaviyo backfills historical orders automatically on connection, which can take anywhere from minutes to several hours depending on your store’s size. Let this finish before moving on, since flows and segments you build afterward will rely on that data being complete.
Check that key ecommerce events are firing correctly — Placed Order, Started Checkout, Viewed Product — by placing a small test order and confirming it appears on the profile in Klaviyo.
Screenshot
Klaviyo Integrations page showing store connection and sync status
Step 2: Export non-store contacts from Mailchimp
Not every Mailchimp contact will exist in your store’s order history — people who joined through a newsletter form, a giveaway, or a lead magnet need to be exported separately and imported manually since the store sync will not pick them up.
Go to Audience → All contacts in Mailchimp and export the full subscribed list, along with unsubscribed and cleaned contacts for suppression purposes.
Filter or tag this export mentally as "non-transactional" contacts — you will import them as profiles without order history, which is a genuinely different segment in Klaviyo than your customers.
Screenshot
Mailchimp Audience export screen filtered to newsletter signups
Step 3: Import contacts and reconcile with store profiles
In Klaviyo, go to Lists & Segments and import your Mailchimp CSV. Klaviyo matches incoming contacts to existing profiles by email address, so anyone who already exists from the store sync gets merged rather than duplicated.
Map your Mailchimp custom fields to Klaviyo properties as you import. Tags typically translate best as either a list membership or a custom property depending on how you plan to segment.
Import your unsubscribed and cleaned contacts and suppress them in Klaviyo immediately, before any campaign or flow can reach them.
Screenshot
Klaviyo contact import screen with field mapping
Step 4: Rebuild your flows
Nothing transfers automatically. Go back to the list of Mailchimp automations you documented and prioritise by revenue impact: welcome series, abandoned cart, browse abandonment, and post-purchase are the flows that typically carry the most weight for a store.
In Klaviyo, Flows → Create Flow gives you triggers built directly around store events — Started Checkout, Placed Order, Ordered Product — that Mailchimp’s more generic automation triggers cannot match precisely, so this is often where the rebuild actually improves on the original.
Recreate delay timings carefully rather than guessing. Klaviyo’s time-delay steps are configured slightly differently to Mailchimp’s, and a miscounted delay can send an entire abandoned cart sequence within minutes instead of hours.
Rebuild templates in Klaviyo’s editor rather than pasting Mailchimp HTML — product blocks and dynamic pricing tags need to be rebuilt using Klaviyo’s own dynamic content tags, which do not carry over from pasted markup.
Screenshot
Klaviyo flow builder showing an abandoned cart sequence
Step 5: Update forms and integrations
Replace embedded Mailchimp signup forms with Klaviyo forms, since the two use different posting structures and field names.
Check any app connected to Mailchimp through your store platform — reviews apps, loyalty programmes, SMS tools — and reconnect them to Klaviyo where an integration exists.
Leave Mailchimp connected in a read-only sense for a couple of weeks and watch for any new signups landing there, which tells you a form was missed.
Screenshot
Klaviyo signup form builder embedded on a store page
Step 6: Test every flow against a real order
Add a product to cart and abandon it deliberately to confirm the abandoned cart flow triggers with the right delay and the right product shown in the email.
Complete a separate test order fully and confirm the post-purchase flow, including any review request or replenishment reminder, fires on schedule.
Check revenue attribution is appearing against the correct flow in Klaviyo’s analytics before you rely on those numbers for reporting.
Screenshot
Klaviyo flow analytics showing revenue attributed to a test order
Step 7: Cut over campaigns and retire Mailchimp
Send your first regular campaign from Klaviyo to a smaller, engaged segment first, checking deliverability across major inbox providers before opening it up to your full list.
Turn off the equivalent Mailchimp automations once you have confirmed the Klaviyo flows are live and firing correctly, so customers do not receive duplicate emails from both platforms.
Once two weeks pass with no new signups appearing in Mailchimp and no missed events, export a final backup and cancel the subscription.
Screenshot
Klaviyo campaign report for the first live send
Integrations you need to update
Every one of these is a place contacts or data currently flow into Mailchimp. Work through the list before you stop watching the old account — a missed form is invisible until someone complains they never got your email.
| Integration | What to do |
|---|---|
| Shopify / WooCommerce | Connect first, before any contact import, so profiles carry full order history. |
| Website signup forms | Replace Mailchimp embeds with Klaviyo forms and confirm a live test submission. |
| Reviews apps | Reconnect review request triggers to fire from Klaviyo’s post-purchase flow instead of Mailchimp. |
| SMS providers | Consider consolidating into Klaviyo’s native SMS rather than running a separate tool. |
| Loyalty and subscription apps | Reconnect to sync membership and subscription status onto Klaviyo profiles. |
| Zapier / Make | Rebuild scenarios using the Klaviyo connector, since Mailchimp-based Zaps will not remap automatically. |
| Facebook / Instagram lead ads | Reconnect lead forms directly to Klaviyo so new leads stop landing in Mailchimp. |
| Customer support / helpdesk | Update API keys and confirm profile data syncs correctly in both directions. |
Troubleshooting: common post-migration problems
Profiles are missing order history after the store sync
Check the integration sync status in Klaviyo’s Integrations tab — large catalogues or order histories can take several hours to backfill fully before profiles are complete.
Abandoned cart flow fired within minutes instead of hours
The delay step was misconfigured during rebuild. Open the flow, check the time delay filter, and adjust it to match your intended window.
Duplicate profiles for the same customer
Usually caused by importing contacts under a different email format than the store order. Merge manually in Klaviyo’s profile view or re-import with consistent email casing.
Revenue attribution looks wrong in flow analytics
Confirm the Placed Order metric is properly integrated and that your store’s currency settings match between the store and Klaviyo account.
Klaviyo bill jumped sharply after migration
Active profile counts include anyone Klaviyo can message, including old customers with no recent activity. Suppress or archive genuinely dormant profiles to bring the count down.
New signups still appearing in Mailchimp weeks after cutover
A form or checkout opt-in was never repointed. Check the source of the new Mailchimp contact to identify which one.
Should you make the switch?
The migration itself is rarely the hard part — it is the automations you rebuild and the forms you forget. If the reasons in the "switch if" list above describe your situation, Klaviyo is worth the afternoon. If you are only moving because you are frustrated with an interface, fix the emails first and keep the platform.
Read both sides before you commit: our Mailchimp review covers what you would be giving up, and our Klaviyo review covers what you are buying, including current pricing and where it falls short. Every switch we document is listed on the migration guides hub.