10 Best Email List Building Tools for Online Stores in 2026

The best email list building tools for online stores are OptiMonk, Klaviyo sign-up forms, Omnisend, Privy, Mailchimp, Sleeknote, Wisepops, Poptin, Getsitecontrol and OptinMonster.

We make one of these tools, so we spend a lot of time looking at the others. The question store owners ask us most is simple: my email platform already has sign-up forms, do I really need another tool? Sometimes the honest answer is no. This guide helps you decide, with real prices from each vendor's own pricing page and the downsides of every tool, our own included.

Popup tools like OptiMonk collect emails and send them to your email platform; all-in-one platforms like Klaviyo collect and send. If you run a store, pick one with cart-based targeting and Shopify discount codes.

Email list building tools at a glance

Prices are from each vendor's own pricing page, as of October 2026.

Tools measure usage in different ways. A pageview is every page loaded, a visitor is one person per month, an impression is every time a campaign is shown, and a contact or profile is everyone on your list. So compare what each plan covers at your own traffic and list size, not just the headline price.

Do you need a list building tool if you already have email marketing software?

Not always. The built-in forms in Klaviyo, Omnisend or Mailchimp are enough to start collecting emails. A separate popup tool is worth it when targeting, A/B testing, gamification and a proper mobile version start to matter.

Email marketing software is built to send: flows, campaigns, segments. Its sign-up forms are one feature among many. A dedicated list building tool is built for the moment a shopper is on your store, so it usually gives you:

• More triggers: exit intent on mobile, cart value, products in the cart, traffic source, returning visitors.
• Testing: A/B tests on the offer, the copy or the whole design, plus holdout tests to see what the popup adds.
• More formats: lucky wheels, scratch cards, surveys and countdowns.
• Revenue reporting: which popup brought subscribers who actually bought.

The two work together. The popup tool collects the email (and often the phone number), then passes it to your email platform, which sends the welcome flow. You don't replace your email marketing software; you feed it.

A simple rule: if your email platform's forms convert well enough and you only need one welcome popup, stay with them. If you want different offers for different shoppers, or you're testing what works, add a popup tool.

If you're choosing the sending platform itself, see our comparison of the best email and SMS marketing software.

Types of email list building tools

There are three kinds of tools that collect emails on a store. The right one depends on how you want to work.

Privy and Wisepops sit in between: Privy sells popups on their own or with email, and Wisepops adds other onsite channels to popups.

For most online stores, a marketing suite is more than they need. This list covers the first two types.

How we chose these tools

We looked at the tools an online store can run on its own and compared them on six things:

• Shopify and store integration: a native app or easy install, a direct sync with your email platform, and Shopify discount codes.
• Formats: classic popups plus lucky wheels, scratch cards, surveys and a separate mobile version.
• Targeting and triggers: exit intent, time on page, scroll depth, cart value, traffic source, returning visitors.
• A/B testing: built in, not an add-on on a higher tier.
• Email and SMS: collecting both in one popup, and sending both to the right tool.
• Price and free plan: what the free plan really includes, and what a growing store pays.

We're OptiMonk, so we put ourselves first. We've tried to describe every tool fairly, including our own downsides.

The 10 best email list building tools

1. OptiMonk

Best for: stores that want more subscribers without designing popups themselves.

OptiMonk is an agentic popup builder for online stores. You describe the popup you want in one sentence, for example "create a welcome popup offering a discount on the first order in exchange for an email address". The AI agent designs it for your brand, writes the copy, and builds a separate mobile version.

Key features

• The agent does the design work. No templates to pick and edit; the agent designs each popup for your brand.
• Formats: popups, fullscreen, lucky wheel, scratch cards, surveys, countdowns.
• 25 targeting rules and triggers: exit intent on desktop and mobile, time delay, scroll depth, cart value and contents, traffic source, returning visitors, subscribers, and Klaviyo lists and segments, so you don't show a signup popup to people already on your list.
• Shopify codes: discount codes, unique codes and codes applied automatically at checkout.
• Testing: A/B tests on the copy, the offer or the whole design, holdout tests and revenue analytics. The agent also suggests what to test next.
• Build from Claude, ChatGPT or Cursor through the OptiMonk MCP server.
• GDPR safe, with double opt-in, and popups that load asynchronously.
• New subscribers go straight to your email or SMS tool.

Pricing (OptiMonk pricing page): Free plan with every feature, up to 10,000 pageviews and 1,000 AI credits a month on one domain. Paid plans from $19/mo billed yearly ($29 billed monthly). Plans differ only in traffic, AI credits and domains. See pricing.

Pros

• No design work: the agent designs each popup and its mobile version
• Store-focused targeting and Shopify discount codes
• Every feature on every plan, including Free

Cons

• It collects emails but doesn't send them, so you also need an email platform
• It only does popups: classic popups, fullscreen popups, lucky wheels and scratch cards. If you also want embedded forms on your pages, side messages or sticky bars, you need another tool

Comparing directly? See OptiMonk vs Privy and OptiMonk vs OptinMonster.

2. Klaviyo sign-up forms

Best for: stores that already send email with Klaviyo.

Klaviyo is an email and SMS platform built for ecommerce. Its web forms collect emails and phone numbers straight into your Klaviyo lists, so the welcome flow starts right away.

Pricing (Klaviyo's pricing page, Oct 2026): web forms are included in the free Klaviyo plan (up to 250 profiles and 500 emails a month). Paid plans start at $20/mo for up to 500 active profiles and grow with your list: $150/mo at 10,000 and $720/mo at 50,000 active profiles.

Pros

• No extra tool if you're already on Klaviyo
• Signups land directly in your lists and segments

Cons

• Forms are one part of an email platform, with fewer formats and targeting options than a popup tool
• Pricing grows with your profiles, not with how much you use the forms

Already on Klaviyo? OptiMonk can show or hide campaigns by Klaviyo list or segment.

3. Omnisend

Best for: small stores that want email, SMS and popups in one place.

Omnisend is an ecommerce email and SMS platform. Popups, teasers, landing pages and embedded sign-up forms are included on every plan, Free too.

Pricing (Omnisend's pricing page, Oct 2026): Free for 250 contacts and 500 emails a month, with a "Powered by Omnisend" badge on emails and sign-up forms. Standard: $16/mo for 500 contacts and 6,000 emails. Pro: $59/mo for 2,500 contacts and unlimited emails. SMS from $0.007 per message.

Pros

• Popups and email in one tool, on the free plan too
• SMS on the Pro plan

Cons

• Omnisend branding on the free plan
• Price grows with your contact list

4. Privy

Best for: Shopify stores that want popups and email marketing in one tool.

Privy combines onsite popups with email and SMS for small and mid-size stores. You can buy the popups on their own or together with email.

Pricing (Privy's pricing page, Oct 2026): no free-forever plan; a 15-day free trial with no card. Pop-ups & Displays only: from $24/mo for up to 10,000 pageviews. Email plans from $30/mo for up to 1,500 contacts, with popups included. Exit intent popups are listed on the popup plan.

Pros

• Popups and email in one place, built for stores
• You can start with popups only

Cons

• No free plan
• Email pricing grows with your contact list

See also: Privy alternatives.

5. Mailchimp

Best for: stores that send simple newsletters and want a free start.

Mailchimp is a widely used email platform with sign-up forms built in. It's a general email tool, not one built for stores.

Pricing (Mailchimp's pricing page, USD, Oct 2026): Free for 250 contacts and 500 emails a month (250 a day). Essentials from $13/mo, Standard from $20/mo. Popup forms are listed on every plan, but marked as a beta with "very limited availability".

Pros

• Free plan and a low entry price
• Easy to learn

Cons

• Popup forms are a beta with limited availability
• Few store-specific triggers such as cart value

Using Mailchimp? See how to add a Mailchimp popup.

6. Sleeknote

Best for: mid-size stores with a marketing team that wants a polished onsite tool.

Sleeknote is a popup tool focused on ecommerce, with a separate Sleeknote for Shopify page.

Pricing (Sleeknote's pricing page, Oct 2026): no free plan; a 14-day free trial with no card. Core: €49/mo billed yearly or €62/mo billed monthly, for up to 25,000 visitors a month. Core + Gamification: €68/mo billed yearly.

Pros

• Ecommerce focus
• Gamification available as a plan

Cons

• No free plan
• Priced in euros; gamification costs extra

See OptiMonk vs Sleeknote.

7. Wisepops

Best for: high-traffic stores that want popups plus other onsite channels and a team to run them.

Wisepops describes itself as an activation platform with six channels, a quiz builder, A/B tests with control groups and 50+ integrations, including Klaviyo and Shopify. You start with a demo; its team sets up the trial.

Pricing (Wisepops' website, Oct 2026): prices aren't published. You request a demo and get a quote, so you can't compare costs before talking to sales. A 14-day trial starts after the demo.

Pros

• Many onsite channels beyond popups
• Hands-on strategy help

Cons

• No public pricing; you need a demo to get a quote
• More than a small store needs

See OptiMonk vs Wisepops.

8. Poptin

Best for: small stores on a tight budget.

Poptin is a popup and form builder with basic email sending.

Pricing (Poptin's pricing page, Oct 2026): Free for 1,000 visitors a month on one domain (250 active contacts, 500 emails). Basic: $25/mo billed yearly ($240/yr) for 10,000 visitors. Pro: $59/mo billed yearly for 50,000 visitors.

Pros

• A usable free plan
• Low entry price

Cons

• Low visitor limit on the free plan
• You design the popup yourself in a drag-and-drop editor

See OptiMonk vs Poptin.

9. Getsitecontrol

Best for: small sites that want simple forms at a low price.

Getsitecontrol builds popups and forms, and can also send emails to the people who sign up.

Pricing (Getsitecontrol's pricing page, Oct 2026): Free for 10,000 widget views a month. Pro: $19/mo for 100,000 widget views. Pro Max: $29/mo for unlimited widget views. Contacts are unlimited on every plan; email sending is billed separately, from $2.00 per 1,000 emails on Free to $1.40 on Pro Max. Yearly billing saves up to 25%.

Pros

• Generous free plan for a small site
• Flat price, unlimited contacts

Cons

• Email sending costs extra
• Fewer store-specific features than ecommerce-focused tools

See also: Getsitecontrol alternatives.

10. OptinMonster

Best for: WordPress sites focused on lead generation.

OptinMonster is a long-standing lead capture tool that grew up on WordPress.

Pricing (OptinMonster's pricing page, Oct 2026): no free plan. Basic: $9/mo billed yearly ($108 for the first year, renews at $210/yr) for 1 site and 2,500 impressions a month. A/B testing starts on Plus ($27/mo), Exit Intent® on Pro ($37/mo), and Shopify and WooCommerce integrations on Growth ($67/mo).

Pros

• Many campaign types and targeting options
• Low first-year entry price

Cons

• Exit intent and store integrations sit on higher plans
• Renewal prices are higher than the first year

More options: OptinMonster alternatives.

Popup tool vs all-in-one email platform: which should you pick?

Pick by what you already have and what you want to improve.

Many stores do both: the email platform sends, the popup tool fills the list.

How to build an email list faster with any tool

The tool matters less than what you put in front of shoppers. Five habits that work with any of the tools above:

• Give a clear reason to sign up. A welcome discount, free shipping or early access. Say it in the headline. More ideas: ecommerce lead magnets.
• Catch people on their way out. An exit-intent popup gives a last offer to visitors who would leave anyway.
• Make it a game. A lucky wheel or scratch card turns a signup into a quick spin. See gamified popups.
• Ask for the phone number too. Collect email first, then the phone number in the same popup, and send each to the right tool.
• Confirm the address. Double opt-in keeps fake and mistyped emails off your list.

A welcome popup designed for Chamberlain Coffee: one offer, one field. See this popup

A lucky wheel designed for Energy Muse: the email field sits next to the wheel. See this popup

For the full playbook, read our email capture best practices, list building strategy and how to build an email list from scratch. For the bigger picture, start with our guide to lead capture.

Email list building tools FAQ

What is an email list building tool?

An email list building tool collects email addresses (and often phone numbers) from your website visitors, usually with popups, forms or landing pages. It then sends each new subscriber to your email platform, so you can reach shoppers directly instead of relying on ads or social media.

What's the best free email list builder?

For an online store, OptiMonk's free plan includes every feature, up to 10,000 pageviews a month. Klaviyo, Omnisend and Mailchimp include sign-up forms on their free plans (250 contacts or profiles), and Getsitecontrol and Poptin have free popup plans with lower limits. Prices as of October 2026.

Is email capture software the same as email marketing software?

No. Email capture software collects addresses on your site; email marketing software sends the emails. Some tools do both, like Klaviyo, Omnisend and Privy. A dedicated capture tool like OptiMonk passes signups to the email platform you already use.

Can I build an email list without a website popup?

Yes. You can use embedded forms, a footer sign-up, a landing page, checkout opt-ins or social media sign-ups. Popups usually collect more signups from the same traffic because they show one offer at the right moment, but the best mix depends on your store.

How do I capture emails on my Shopify store?

Install an email capture app, such as OptiMonk or Privy, and connect it to your email platform. Show a welcome offer (a discount or free shipping) to first-time visitors, add an exit-intent popup, and use a Shopify discount code so the offer works at checkout. If you'd rather build forms only, see our list of Shopify form builder apps.

Start building your email list with OptiMonk

Your first popup is one sentence away. Describe the offer you want to show, and the agent designs the popup for your brand, with a separate mobile version and the targeting you choose. New subscribers go straight to the email tool you already use, like Klaviyo.

Free to start. No credit card.