21.7% of Shopify Stores Run Klaviyo Email Marketing vs 4.9% of All Online Stores

A shopper opens an online store for the first time and, a few seconds in, a box slides over the page offering a discount for her email address. She signs up, adds a pair of boots to her cart and closes the tab. An hour later an email arrives with a photo of the boots and a link back to her cart. The sign-up box, the list it feeds and the reminders that follow are what email platforms like Klaviyo and pop-up tools like OptinMonster or Privy sell.

For a store, an email list is a group of customers it can reach again without paying for an ad each time. Klaviyo collects sign-ups on the website, tracks what each subscriber browses and buys, and sends automatic messages such as welcome emails and abandoned cart reminders. Dedicated pop-up software gives a store control over when the sign-up box appears, who sees it and what it offers. Knowing how many stores run each shows what is standard practice and what is a specialist choice.

Klaviyo's home is Shopify. 21.7% of Shopify stores run it on their homepage, more than one in five, against 4.9% of online stores overall, and Shopify stores make up about 83% of all the stores that run it. Dedicated pop-up software is a specialist choice: 97.7% of online stores run none, and the tools are twice as common on Shopify stores and on stores among the million most visited websites.

We used the public HTTP Archive crawl of September 2026, which loads the homepages of 15,470,478 websites and records the software each one uses. Of those, 3,911,812 are online stores, sites running a store platform or shopping-cart software, and 729,553 of the stores run on Shopify. For each store we checked whether Klaviyo loads on the homepage and whether any of 17 dedicated pop-up tools does, then compared platforms, popularity and country domains.

A store counts as running Klaviyo when any Klaviyo code, such as its sign-up forms or its tracking of visitor activity, loads on the homepage. A dedicated pop-up tool is software built to show pop-up or slide-in forms, such as OptinMonster, Privy, Justuno, Popup Maker, Klaviyo Forms, Wisepops, Poptin, Sumo, OptiMonk and Sleeknote. Popularity comes from Google's Chrome UX Report, which ranks websites by how often real Chrome users visit them. The popularity and country comparisons count all websites in each group, not only stores, so their rates run lower than the store figures.

That is about 158,100 Shopify stores, roughly 83% of the 190,612 online stores that run Klaviyo. Outside Shopify, Klaviyo is rare: 0.4% of WordPress websites and 1.3% of business-to-business websites run it. Klaviyo connects to a Shopify store in a few clicks and pulls in orders, products and customers automatically, which is what makes its automatic emails possible. For stores on other platforms, the setup takes more work and other email tools compete.

Pop-up software follows the same pattern at a smaller scale. 5% of Shopify stores run a dedicated pop-up tool, more than twice the all-store rate, and those 36,475 Shopify stores make up about 40% of every store with one. WordPress websites are the exception: they run pop-up tools at 2.7%, slightly above the store average, helped by pop-up plugins such as Popup Maker, while almost none of them run Klaviyo.

2.3% of online stores load a dedicated pop-up tool, 91,645 stores, about one store in forty. Stores do use pop-up software more than the rest of the web, where 1.3% of websites load it, because a store has something to offer in the box, usually a first-order discount, and a clear use for the email addresses it collects. Klaviyo reaches further, at 4.9% of online stores, and stores without either collect sign-ups through another email platform or a form built into their store theme.

For small stores, the low rates are an opening. Most competitors run neither tool, which leaves room for a well-run email program, with a clear sign-up offer and a same-day welcome email, to stand out.

Both tools rise with store size, up to a point. Online stores among the million most visited websites run Klaviyo 13.7% of the time, more than five times the 2.5% rate of stores ranked outside the top 10 million, and run pop-up tools at 5%. Across all websites, both peak at sites ranked 100,000 to 1 million and fall away at the very top.

The biggest brands build their sign-up forms and email systems in-house and guard the first impression of their homepage, so they rarely buy either tool: Klaviyo does not appear on any of the 1,000 most visited websites. The smallest sites often have no email program to feed. The sweet spot is the growing store: big enough to have a steady flow of visitors worth capturing, small enough to buy a ready-made platform rather than build one.

By country domain, Australian websites lead on Klaviyo at 5.6% and on pop-up tools at 3.3%, more than twice the pop-up rate of German or French websites and about five times their Klaviyo rate.

The pattern follows Shopify's strongest markets, where independent online stores are common and email marketing to shoppers is an established habit. In continental Europe, both tools compete with local email providers and stricter consent rules for marketing messages, and cookie notices already put one overlay on the page, which leaves less room for a second.

If your store runs no email platform, start with the basics before choosing a tool: a sign-up form on the homepage with a clear reason to join, a welcome email that goes out the same day, and an abandoned cart reminder. Those three pieces do most of the work of an email program. If you run a Shopify store, more than one in five of your Shopify competitors already use Klaviyo, so shoppers who browse around will be getting their emails.

A dedicated pop-up tool is not the norm, so do not assume you need one. If your email platform or store theme already includes a sign-up form, test that first. If you do add a pop-up, set it to appear after some engagement, such as time on the page or a scroll, rather than on arrival, make it easy to close on a phone, and keep the form to one field.

Then judge both on revenue, not sign-ups alone: revenue from email as a share of total sales, sign-up rate on the homepage and how many abandoned carts the reminder recovers. A pop-up that adds email addresses but costs sales on the first visit is a net loss. An ecommerce cro agency can test the sign-up form, the offer and its timing against a version with no pop-up at all.

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