Short answer: Klaviyo is built around your shop's data: every order, every abandoned checkout and every product view arrives on its own and can start an automated email. Mailchimp is a general email tool with a Shopify connection; it is cheaper for a very small list and fine if you mostly send a newsletter. The dividing line is automation: once you want more than a welcome email and a basic abandoned-cart reminder, Klaviyo is the easier road. Aimbox is a Klaviyo agency, so treat our opinion as an opinion. Every price and limit below links to its official page, checked on 22 October 2026.
What each one is for
Klaviyo was made for online shops. Its Shopify app has been in the App Store since 2012 and is rated 4.7 from 3,406 reviews (Shopify App Store: Klaviyo, checked 22 Oct 2026). When you connect your shop, Klaviyo first pulls in the last 90 days of your orders, then your full history, and after that new data arrives in real time: orders placed, checkouts started, products viewed, items added to the basket, parcels shipped (Klaviyo: Shopify data reference, updated 18 Nov 2025, checked 22 Oct 2026). Any of those can start an automated email, and you can group customers by what they did (that is all a "segment" is: people who bought twice, people who have not bought in 90 days).
Mailchimp started as a newsletter tool for every kind of business and added shop features later. Its Shopify app is rated 4.8 from 1,527 reviews (Shopify App Store: Mailchimp, checked 22 Oct 2026). Once connected it adds each customer's email, name and order information to your audience and starts syncing "some customer behavior, such as what pages your customers visit" (Mailchimp: Connect or disconnect Mailchimp for Shopify, checked 22 Oct 2026).
There is a third option many owners forget: Shopify Email, already inside your admin. 10,000 emails a month are free, then $1 per 1,000 (Shopify Email pricing, checked 22 Oct 2026). Good for a newsletter; limited for automation.
Price for a typical small UK shop
Three things decide your bill: how many people you pay for, how they are counted, and the currency.
Klaviyo. Free up to 250 active profiles and 500 emails a month. Paid email plans start at $20 a month for 251 to 500 active profiles, and the price rises in steps with your list (Klaviyo pricing · Shopify App Store: Klaviyo, checked 22 Oct 2026). Klaviyo bills in US dollars even on its UK pricing page (the App Store listing says "all charges are in USD"), so your pounds depend on your card's exchange rate. An "active profile" is anyone you can email; suppressed profiles, people you have stopped emailing, are not charged (Klaviyo: Understanding active profile management, updated 30 Mar 2026, checked 22 Oct 2026). Go over your plan and Klaviyo upgrades you automatically at the end of the billing cycle (Klaviyo: How Klaviyo billing works, updated 20 Oct 2026, checked 22 Oct 2026).
Mailchimp. Free up to 250 contacts and 500 sends a month. On 22 October 2026 the pricing page, set to pounds, showed Essentials at £9.83 a month and Standard at £15.12 a month for the smallest tier (0 to 500 contacts), both labelled "for 12 months"; the price after that was not shown. Monthly sending is capped at 10 times your contacts on Essentials and 12 times on Standard (Mailchimp pricing, checked 22 Oct 2026). The catch is in the counting: "Subscribed, unsubscribed, and non-subscribed contacts are included in your contact count" (Mailchimp: About Mailchimp pricing plans, checked 22 Oct 2026). Archived contacts do not count, but you have to archive them yourself.
The working, for a 1,000-person list. Say 1,000 people are on your list, 200 have unsubscribed over the years, and 800 can still be emailed. In Mailchimp you pay for 1,000 contacts (its 501 to 1,500 tier) unless you archive the 200. In Klaviyo you pay for 800 active profiles. At 5,000 the same logic applies, and the gap grows with every unsubscribe you forget to archive. Both pricing pages show the exact 1,000 and 5,000 prices only when you move a slider in a browser, so we will not print a number we have not seen: set your own list size on each and compare the totals.
Shopify integration
Klaviyo creates "a unique profile for every customer" it syncs, and its abandoned-cart emails are started by the Checkout Started event; order follow-ups use Placed Order and shipping updates use the fulfilment events (Klaviyo: Shopify data reference, checked 22 Oct 2026). In plain terms: the shop and the email tool share one memory.
Mailchimp syncs customers, orders and page visits in real time, discount codes "every few hours", and connects one store per audience. If you reconnect the store, existing abandoned-cart automations have to be recreated (Mailchimp: Connect or disconnect Mailchimp for Shopify, checked 22 Oct 2026). Shopify's own customer segments can be synced across, and Mailchimp discount codes sync back to Shopify (Mailchimp for Shopify, checked 22 Oct 2026).
Automated emails (flows)
This is where the two part ways. Mailchimp's Free plan has no automations; Essentials allows "up to 4 flow steps"; Standard allows up to 200 flows (Mailchimp pricing, checked 22 Oct 2026). So a proper welcome series plus an abandoned-cart series plus a post-purchase email means the Standard plan.
Klaviyo's free plan inside Shopify allows 3 automated messages live at once and 1 live sign-up form, with "Powered by Klaviyo" branding; a paid plan lifts the limits and removes the branding (Klaviyo: free plan limits in Klaviyo Starter, updated 21 Sep 2026, checked 22 Oct 2026).
Sign-up forms, reviews and SMS
Sign-up forms: both have pop-ups and embedded forms on the free plan; Klaviyo's free plan limits you to one live form (sources above).
Reviews: Klaviyo Reviews is an add-on from $25 a month for up to 250 orders a month, Shopify and WooCommerce only, and you must be on a paid Klaviyo email plan (Klaviyo Reviews, checked 22 Oct 2026). Mailchimp has no review product of its own; its Shopify listing names Judge.me and Yotpo under "works with".
SMS: Klaviyo's free plan includes $5 of mobile messages a month, and the App Store lists SMS from $15 a month for up to 1,250 credits (listing, checked 22 Oct 2026). Mailchimp offers SMS as an add-on on Essentials and above and covers the UK, but shows no UK prices (Mailchimp: About SMS marketing, checked 22 Oct 2026). Either way, UK text messages need the customer's clear permission.
Deliverability: will my emails reach the inbox?
Both can reach the inbox and both can miss it. Both start you on a shared sending address and both let you send from your own domain, the single change that matters most; Klaviyo recommends it for any account over 5,000 profiles (Klaviyo deliverability reference, checked 22 Oct 2026). A visible unsubscribe link and a clean list do the rest. If your emails already land in spam, moving platform will not fix it; read why Shopify emails go to spam first.
Who should stay on Mailchimp
Stay if you send a newsletter once or twice a month and little else; if you have under 500 contacts and price matters most; if you sell services rather than products; or if your team knows Mailchimp and reads its reports. A move costs time. If your numbers are fine, do not move.
Signs you have outgrown Mailchimp
- You have hit the "up to 4 flow steps" wall on Essentials, or you pay for Standard only for automations.
- You pay for people you cannot email, because unsubscribed contacts count.
- You want emails based on what people bought or looked at: browse reminders, back in stock, "time to reorder".
- You want reviews, text messages and email in one place.
- You build customer groups by hand in a spreadsheet and upload them.
Two or more of these and it is time to compare properly: not because Klaviyo is magic, but because automated emails run every day without you.
What to do first
- Write down three numbers: contacts, how many of them you can no longer email, orders a month.
- Open both pricing pages with your own list size and compare the totals.
- List the automated emails you want in the next six months. More than a welcome email and an abandoned-cart reminder: Klaviyo. Fewer: stay.
- Do not switch in the middle of your busiest season. Plan the move for a quiet month.
A move is a project, not a setting: your list, forms, flows and sending domain all need to come across in the right order. That is what our Klaviyo Launch Pack does, from £350 (pricing). Not sure yet? Send us your shop's address for a free email health check and we will tell you, in plain English, whether moving is worth it for you.
Common questions
Is Klaviyo more expensive than Mailchimp?
For the smallest lists, usually yes: Mailchimp's Essentials plan started at £9.83 a month for up to 500 contacts and Klaviyo's paid email plan at $20 a month for up to 500 active profiles on 22 October 2026. As the list grows the gap narrows, because Mailchimp counts unsubscribed contacts in your bill and Klaviyo does not charge for suppressed profiles.
Can I use Klaviyo for free with my Shopify shop?
Yes. Klaviyo's free plan covers up to 250 active profiles and 500 emails a month, with 3 automated messages live at once and 1 live sign-up form, and "Powered by Klaviyo" branding on your emails. Reach the monthly email limit and sending pauses until the next month or an upgrade.
Does Mailchimp still work with Shopify in 2026?
Yes. The official Mailchimp app on the Shopify App Store syncs customers, orders and page visits, supports abandoned-cart reminders and product recommendations, and connects one store per audience. Marketing automation flows need a paid plan.
Should I switch from Mailchimp to Klaviyo before Black Friday?
Only if you can finish the move well before the season starts. Flows, forms and your sending domain all need to be rebuilt and tested on the new platform, and switching during your busiest weeks risks a sales dip. Plan the move for a quiet month and run it as a project.