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I’ve Tested 6 Email List Building Tools And Here’s What I Found

This image is a symbolic graphic representation of email list building tools for an article that covers the topic in detail.

You could build an email list using something as simple as Google Forms, and technically, it works. 

But here’s the thing: if you want an email list that grows fast, converts well, and actually drives revenue, you’ll need a tool that’s purpose-built for it.

In this guide, I won’t be discussing makeshift workarounds; I’ll present some dedicated email list building tools that are packed with the essentials: smart targeting, popups that convert, deep integrations, and automation that does the hard work while you sleep. 

Disclaimer: The reviews in this write-up reference feature offerings, software catalog ratings and pricing. These were valid at the time of writing but could be subject to change by the time you’re rading the article.

Email list building tools: a snapshot

Click on a platform name to jump to the detailed review.

And here’s a side-by-side comparison of the email list-building tools

PlatformPopup & form builderA/B testingBehavioural targeting Pricing 
OptinMonsterYesYesYes$7/month
OptiMonkYesYesYes$29/month
SleeknoteYesYesYes$69/month
MailchimpYesBasicLimited$4.63/month
HubSpotYesYesYes$20/month
KlaviyoYesYesYes$45/month

Email list building tools: comparison criteria

Not every email list-building tool works the same way, and not every marketer needs the same thing. To help you choose the right one, here’s how I evaluated each tool in this guide:

Selecting service type

Service type is the first thing to check since it largely affects how you use it.

Some tools in this list, like OptinMonster, OptiMonk, and Sleeknote, are dedicated popups and form builders. They help you capture email addresses directly from your website using smart triggers, beautiful forms, and personalization. That’s it.

The given tools don’t send emails, manage your campaigns, or do list segmentation. Instead, they plug into your existing email marketing tool, so if you already use something like Mailchimp or Klaviyo, these can be powerful add-ons that boost your list growth.

Conversely, tools like Mailchimp, Klaviyo, and HubSpot are like all-in-one email marketing platforms. They give you the full toolkit: popups, email sending, automation, segmentation, SMS, and CRM under one roof. These are great if you want to avoid juggling multiple tools and just want one place to manage your audience from signup to sale.

So while comparing, I grouped the tools into two categories:

This helped me evaluate each tool based on what it’s actually meant to do.

Pricing

Pricing is important to determine what you get from the tool at each tier. It also affects the service cost when your business scales, increasing the demand for list building. Also, I focused on whether the “free plans” are genuinely useful. 

Particularly, I looked at the following:

For instance, Mailchimp and Klaviyo offer free plans that are great for getting started. You can collect emails, send basic campaigns, and try out automation. But as your list grows, so does your bill.

Others like OptinMonster or Sleeknote don’t offer a free plan at all. Instead, they give you a short trial or a money-back window, which is fine if you want to test the waters. 

Email list-building features

When checking the tool’s core list-building capabilities, here’s what I paid close attention to:

AI and integrations

AI is helpful in email list building, not for writing your emails (though it can help there, too). But, in this context, it can make your forms smarter, segments sharper, and data cleaner from day one.

Here’s what I looked for:

The integrations relate to how easily each tool connects with email marketing platforms, CRMs, and e-commerce stores. A good integration means new contacts are automatically added to the right segment, tagged properly, and ready to receive relevant emails.

Also, bonus points went for tools that sync behavioural data, product views, or even quiz responses to personalize sign-up forms in real time.

User experience 

While testing each platform, I considered how smooth the experience was, especially when setting up forms, customizing campaigns, and managing contacts day to day.

Here’s what I examined:

Legal compliance 

Legal compliance isn’t optional, especially when you’re collecting personal data like emails. 

I checked if each tool supports:

Customer experience 

I started by reading through dozens of reviews on platforms like G2, Capterra, and even Reddit. These gave me an unfiltered insight into what users love, what frustrates them, and what they wish the tool did better. I paid special attention to recurring themes, whether people praised the UI, ranted about bugs, or appreciated how quickly support responded.

Next, I tested how accessible the support is. Some tools offer live chat on nearly every page, while others hide support behind paywalls or limit it to email-only help. I noted whether basic plan users could still reach someone when needed, and how clear the escalation path was.

I also spent time exploring each platform’s help centre and documentation. So I looked at how easy it was to find setup tutorials, walk-through videos, form guides, and answers to common issues like trigger settings or integration errors.

Additionally, I considered brand credibility and real-world results. If a tool had been used by known brands or they shared measurable success stories (like massive list growth or conversion lifts), that gave me confidence it wasn’t just marketing fluff.

Continuing with the discussion, let’s now explore the tools I’ve lined up for you in greater detail.

OptinMonster

G2: 4.4 🌟 Capterra: 4.2 🌟

OptinMonster is built with one thing in mind: to help you turn your website visitors into email subscribers, and it’s really good at it. With its drag-and-drop builder, 700+ professionally designed templates, and smart targeting options (like exit intent, scroll depth, or time on page), you can easily show the right offer to the right visitor at the perfect time. 

Also, whether it’s popups, slide-ins, floating bars, or full-screen welcome mats, you can personalize every form and conduct A/B testing. You also get advanced rules like page-level targeting and geo-location, besides features like MonsterLinks™ for two-step opt-ins and content locking to gate high-value material. 

It integrates with nearly every email platform and CMS and even includes TruLead™ to filter out fake signups. 

Pros

Cons

Pricing 

OptinMonster offers four pricing tiers, billed annually:

PlansPrice per monthSitesPage views Key features
Basic$712,500Drag-and-drop builder, basic popups, 700+ templates, standard integrations
Plus$19210,000A/B testing, content locking, Yes/No forms, device targeting, and advanced rules
Pro$29325,000Exit intent, MonsterLinks™, countdown timers, revenue tracking, live support
Growth$4951,00,000Geotargeting, adblock detection, personalization, follow-up campaigns, logins

Note: All plans come with unlimited campaigns and subscribers, with no additional subscriber fees.

For more details, check out the OptinMonster official pricing page

Customer experience 

OptinMonster receives positive feedback on platforms like Capterra and Reddit. Some users praise its simplicity and performance for fast campaign rollouts, while others highlight its rich form options and exit-intent performance. 

OptiMonk

G2: 4.8 🌟 Capterra: 4.9 🌟

OptiMonk is a conversion-focused pop-up builder. It’s great for making privacy-friendly pop-ups to build email lists through highly targeted on-site messages. Whether you use it to reduce cart abandonment or capture first-time visitors, OptiMonk gives you full control over when, where, and how your campaigns show up. 

The service has 300+ pre-optimized templates and one of the best A/B testing systems out there. You can test and tweak your popups for higher conversions using a straightforward interface and analytics dashboard (albeit pretty basic). Its drag-and-drop builder is beginner-friendly and powerful enough to handle advanced targeting. The builder includes cart value, page behaviour, referral source, and more. 

You can collect rich first-party data with multi-step forms and custom fields (beyond email). And the best part is that you can sync it all with tools like Klaviyo, Mailchimp, or HubSpot. 

Lastly, the tool itself is GDPR and AdBlock compliant.

Pros

Cons

Pricing 

OptiMonk offers a forever-free plan and a 14-day free trial on paid plans. All plans include unlimited campaigns, users, and access to all features.

See the table for more details: 

PlansMonthly priceAnnual pricePage views/monthDomainsKey features
Free$0$010,0001All popup types, unlimited campaigns, basic targeting, unbranded, email support
Essential$29$22830,0002Advanced targeting, A/B testing, scheduling, analytics
Growth$99$8281,00,0004Custom fonts, visitor segmentation, advanced integrations
Premium$249$1,7885,00,00010Enterprise features, priority support, unlimited domains

Want a closer look? You can explore all plan details on OptiMonk’s official pricing page.

Customer experience 

OptiMonk earns consistent praise for its intuitive design, conversion-focused features, and excellent customer support. Users frequently highlight how easy it is to build popups and launch high-performing campaigns even without technical expertise.

Sleeknote

G2: 4.3 🌟 Capterra: 4.8 🌟

Sleeknote lets you create popups, slide-ins, and teasers that feel like a part of your site, not a random interruption. You can build anything from simple newsletter signups to fun gamified campaigns like “Spin to Win” with zero coding. 

Its drag-and-drop builder is easy to figure out, even if you’re not technically inclined. You can personalize messages based on user behaviour like showing a discount only to visitors who’ve been scrolling for a while or are about to leave. You also get A/B testing, scheduling, and detailed targeting to make sure your messages hit the mark. 

Sleeknote integrates nicely with tools like Mailchimp, Klaviyo, and HubSpot, and works well with Shopify and WordPress too. 

Pros

Cons

Pricing 

Sleeknote offers a 14-day free trial with full feature access. Pricing is based on your monthly visitor count, and every plan includes unlimited campaigns, domains, and support.

Monthly visitors Core Plan (billed monthly)+ Gamification (monthly)
0 – 25,000$69/month$95/month
25,000 – 50,000$83/month$115/month
50,000 – 125,000$155/month$205/month
125,000 – 200,000$240/month$305/month
200,000 – 300,000$319/month$405/month
300,000 – 500,000$470/month$610/month
500,000+Custom pricing Custom pricing 

Want to explore plan features? Check out the full Sleeknote pricing page.

Customer experience 

Sleeknote consistently garners praise for its user-friendly interface and effective lead-generation capabilities. Users across various platforms highlight its ease of use, customizable templates, and responsive customer support.

Mailchimp

G2: 4.3 🌟 Capterra: 4.5 🌟

Mailchimp is a powerful all-in-one marketing platform that simplifies email list management and building through its intuitive form builder. You can create embedded forms, popup forms, or full landing pages, all of which are mobile-responsive and customizable to match your brand. Their drag-and-drop interface is beginner-friendly, while advanced users can access custom HTML editing. 

What sets Mailchimp apart is how seamlessly it connects your lead generation to personalized email campaigns. Using advanced targeting filters, you can control who sees which forms based on user behavior, traffic source, or device. Every lead captured flows straight into Mailchimp’s Smart CRM, where you can segment audiences and launch automated campaigns tailored to specific cohorts. 

Pros

Cons

Pricing 

Mailchimp offers four plans based on your needs and the number of contacts. 

PlansStarting priceContacts includedMonthly email sendsBest for
Free$0/monthUp to 500 contacts1,000/month Beginners testing email marketing
EssentialFrom $4/monthUp to 50,000 contacts with $385/mo tier5,000/month Basic list-building and automation needs
StandardFrom $6/monthUp to 100,000 contacts with $800/mo tier6,000/month Enhanced automation, testing & optimization
PremiumFrom $162/monthContact us for a custom plan1,50,000/month Large lists, advanced segmentation and analytics

Need more details? Explore the full Mailchimp pricing breakdown.

Customer experience 

On Reddit, some users have shared mixed experiences, with comments about the platform being suitable for simple email marketing needs but lacking in more advanced functionalities.

Overall, users appreciated Mailchimp’s intuitive design and automation capabilities, such as the Customer Journey Builder, for saving time and enhancing engagement.​

HubSpot

G2: 4.4 🌟 Capterra: 4.5 🌟

HubSpot isn’t just another email tool; it’s the Swiss Army knife for growing and managing email lists at scale. With drag-and-drop forms, popup builders, and embedded CTAs that plug directly into its Smart CRM, every lead captured is instantly actionable. 

You can easily segment your list based on user behavior or where they are in their journey. And when it’s time to send personalized follow-ups based on their interactions, like clicks or page views, HubSpot makes it seamless.

The tool’s real magic lies in how it connects your forms, email workflows, and contact records in one place without any clunky APIs or manual CSVs.

Pros

Cons

Pricing 

HubSpot’s pricing for email marketing is a part of its Marketing Hub, which offers tools like form builders, landing pages, automation, list segmentation, and analytics.

PlansStarting priceIncludes
Free$0/monthUp to 2,000 email sends/month, basic forms, CRM integration, and templates
StarterFrom $20/month (billed annually)1,000 marketing contacts, email health insights, and ad retargeting tools
Professional From $800/monthAdvanced automation, custom reporting, smart content, A/B testing, and more
EnterpriseFrom $3,600/monthRevenue attribution, multi-touch campaigns, team permissions, and AI tools

You can explore more details or build a custom plan using HubSpot’s pricing calculator.

Customer experience

Many users appreciate how easy it is to capture leads using customizable forms, and how the system then automatically organizes those leads into segmented lists for targeted email campaigns.

Klaviyo

G2: 4.6 🌟 Capterra: 4.6 🌟

Klaviyo is purpose-built for eCommerce businesses that want to build, segment, and monetize their email lists. It combines email and SMS marketing into one intelligent platform, enabling brands to capture leads through high-converting popups, embedded forms, and gamified opt-ins, all of which are fully customizable and behavior-triggered. 

Once collected, subscriber data is automatically enriched with shopping behavior, site activity, and past purchases, allowing for granular segmentation. This makes sending personalized campaigns and automated flows like welcome series, cart reminders, or product recommendations possible

Klaviyo’s drag-and-drop editor, pre-built templates, and dynamic product feeds reduce design time and boost performance. Its tight integrations with platforms like Shopify, WooCommerce, and BigCommerce ensure real-time data sync for more informed targeting. 

Pros

Cons

Pricing 

Klaviyo charges based on active profiles, i.e., the number of contacts you plan to email. Pricing scales as your list grows, and you can choose between Email-only or Email + SMS plans. Here’s a complete breakdown:

Plan typeContacts Email per monthMonthly costKey features
Free planUp to 250500$0Signup forms, drag-and-drop builder, basic reporting, 60-day email support
Email plan1,001–1,50015,000$45Core email tools, AI features, 350+ integrations, reporting dashboard
Email+ SMS plan1,001–1,50015,000$60Everything in the Email Plan + SMS campaigns
Add-ons (optional)$100-$500$100/mo: Marketing analytics; $500/mo: Advanced CDP

Klaviyo does not offer a traditional free trial, but the free plan is a great way to test the platform before committing.

For real-time calculations, visit Klaviyo’s Pricing Page or use their built-in ROI calculator.

Customer experience 

Klaviyo earns applause from users across platforms. And I can attest to that, but again, note that it’s one of the most complex to use for inexperienced marketers. Once you get the hang of it, you’ll understand exactly what these people praise. 

Build smarter, not harder

At the end of the day, the best email list-building tool is the one that fits your business goals and growth stage. 

Whether you’re looking for deep segmentation, drag-and-drop ease, or tight CRM integration, there’s always a tool that can fulfill your needs. 

So, go beyond generic forms. Build with intention, test what works, and let your list grow on autopilot.

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