Klaviyo's MailChimp integration is designed to help you as you move from MailChimp to Klaviyo. We don't recommend using both platforms at once other than during the interim period as you make the switch.
We also have a general checklist that covers how to completely migrate over to Klaviyo from a different email service provider (ESP) here.
Find Your MailChimp API Key
First, you'll need to obtain your MailChimp API key. You can get your MailChimp API key by logging into MailChimp, clicking your account name in the upper left, then navigating to Account Settings > Extras > API keys.
On the API key page, create a new API key and copy it. The field you'll need will be a long string of letters and numbers.
Enable the MailChimp Integration in Klaviyo
Once you've obtained your API key from MailChimp, go into the Integrations tab of your Klaviyo account. Here, find MailChimp on the All Integrations list. Click Add Integration and enter your API key.
Once you've pasted in your API key and clicked connect, data will start syncing over within a minute or two. If you click on the Metrics tab in your account, you should see the following MailChimp metrics appear:
- Received Email
- Opened Email
- Clicked Email
The MailChimp Metrics
The MailChimp Clicked Email metric will track email click events synced from MailChimp. To segment this metric further, and see which contacts clicked which specific URLs in your emails, click on the Clicked Email metric in your Metrics tab and then use the advanced filters option to filter by URL.
The MailChimp Opened Email metric will track email open events synced from MailChimp.
Klaviyo will sync a MailChimp Received Email event every time someone successfully receives an email sent from MailChimp (meaning the email was delivered to their inbox).
Understanding Your MailChimp Data
From MailChimp, Klaviyo pulls in:
- When someone received, opened or clicked a particular email
- A list of emails who have unsubscribed or bounced
- Existing lists in MailChimp
- Contacts' MailChimp Ratings
If you choose the sync existing lists from MailChimp to Klaviyo, you can choose to either sync all of your lists or only specific lists.
If you choose to sync only specific lists AND you enable the option "Collect open and click data for MailChimp campaigns," all contacts in your MailChimp account will be imported into Klaviyo -- regardless of whether or not they're in the specific lists you've chosen to sync. So, while syncing specific lists will recreate them in Klaviyo, it will not necessarily limit the number of contacts imported from MailChimp.
Keep in mind that only names and email addresses will sync; to migrate over custom properties that may be attached to contact profiles in MailChimp, see below.
If you delete people in MailChimp, they will not be deleted in Klaviyo. However, if someone is added to a MailChimp list, they'll be added to Klaviyo within an hour. We receive historical data from MailChimp from the last 90 days; if you are syncing a large number of contacts from MailChimp, this may differ.
The integration brings data over every 30 minutes for lists. For campaigns, it pulls data every 15 minutes on the first day and checks less frequently as time passes.
Import Custom Profile Properties into Klaviyo
If you choose to sync existing subscriber lists into Klaviyo through the Klaviyo MailChimp integration, any custom properties attached to these contacts in MailChimp will not automatically flow into Klaviyo.*
*The one exception to this is contacts' MailChimp Ratings. These will be added to contact profiles automatically as custom properties. See below for more information on MailChimp Ratings.
If you want to preserve and migrate your own custom properties when you switch over to Klaviyo, you will need to manually import them to ensure that the correct properties are appended to their contact profiles in Klaviyo. To do this, follow this guide.
Klaviyo pulls in contacts' "MailChimp Ratings," which rate a contact's level of engagement on a scale of 1-5 stars. A contact with 5 stars is considered highly engaged, while a contact with only 1 star is considered unengaged.
Learn moreTo learn more about how MailChimp Ratings are calculated, check out MailChimp's documentation.
To avoid encountering deliverability issues, segment your contacts from MailChimp based on their MailChimp Rating to ensure that you are sending to an engaged list. You can do this by building a segment where the conditions are:
MailChimp Rating is at least 4
If you email your subscribers more than once a week, send to this segment for at least the first week.
If I delete people in MailChimp, are they deleted in Klaviyo?
If I unsubscribe someone in MailChimp, are they unsubscribed in Klaviyo?
Yes. If someone is suppressed in just one MailChimp list, they will be suppressed globally in Klaviyo.
If I unsubscribe someone in Klaviyo, are they unsubscribed in MailChimp?
If I add someone to a list in MailChimp, are they added to a list in Klaviyo?
Yes, after 30 minutes.
If I add someone to a list in Klaviyo, are they added to a list in MailChimp?