Opt-in Form Types: How to Choose the Best Form for Your Site

Momina Ayaz
Momina Ayaz

Last updated on

February 8, 2023

No matter how small or big your business, building an email list is the easiest way to market your products. For that, you need to place opt-in forms on your website.

But with so many different types to choose from, marketers have a tough time deciding which opt-in form types will best serve their needs.

Varying sales requirements and visitor behaviors mean that there’s no one-size-fits-all for opt-ins. So how do you choose the right opt-in form your goals? Let’s find out.

Opt-in forms: An introduction

Email marketing still continues to be a major source of conversions for online businesses. This is no surprise when 82% of internet users check their inboxes at least once a day.

This staggering statistic is clear evidence of why online businesses want to consistently build their email lists. It’s their best shot at grabbing their prospect’s attention.

But how do you build your email list? It all starts with opt-in forms.

Opt-in forms are a great way of collecting emails from website visitors. You place a neat form on your website, asking visitors if they’d like to join your list. Often, this request is paired with an incentive, like a coupon, a resource, or a loyalty program, in exchange for their email address.

Here’s the MailMunch blog’s opt-in form that tells visitors what to expect from the emails and pulls them in with information that is relevant to them.

opt-in form types: mailmunch pop-up form

Emails from these forms then enable companies to communicate with an engaged prospect in the future. It gives them the perfect opportunity to nurture a relationship, market products, and ultimately nudge leads towards a purchase.

Design Considerations

While opt-in forms have immense potential, there are certain best practices to follow when creating any kind of opt-in. Here are the most important ones:

  • Choose a visually appealing, minimalistic design. Your opt-ins should be easy on the eyes, especially when they’ll interrupt browsing.
  • Stick to as few fields as possible. A lot of the times, all you need is an email address, but if you want extra information, only ask for data that you need.
  • Provide an offer, like a resource or a discount coupon, so your visitors get something instantly in return and are driven to sign up.
  • For active opt-in forms (that abruptly flash before visitors), set up display rules that only show the opt-in once the visitor has interacted with the site. For example, showing up 10 seconds after the visitor lands.
  • Users should be able to easily navigate away from the opt-in, so try to place a prominent exit button.

Now that we know the basics, let’s explore our options.

Opt-in form types


Pop-ups are the most popular type of opt-in forms and often the highest converting as well. This makes them a safe choice for new businesses that are skeptical of experimenting with opt-ins and unsure which form type would work for them.

Pop-ups appear as a small lightbox in the center of the screen mid-scrolling. These interrupt scrolling and can be triggered when a user lands on the page or is about to leave.


  • Demands attention
  • Good for lead generation


  • Interrupts reading

Popularly used for:

  • Primary lead generation, promotions, exit-intent strategy, resources

Here’s SurfStitch’s popup form in action. It’s triggered after 10 seconds of engagement.

surfstitch pop up

Site covers

A site-cover is almost like a bigger, much bigger pop-up. It covers the site, as the name suggests, bringing instant attention to it. This form disrupts user scrolling and might appear aggressive at times so marketers should use this carefully. However, there’s no chance of missing it, so it could still generate a lot of leads.


  • Grabs the most attention of any opt-in form
  • Great for tasks that require instant action
  • Works well with all visitor types, new and returning


  • Can seem like a nuisance because of its aggressive nature

Popularly used for:

  • Primary lead generation, promotions, flash sales, limited time offers

Here’s Neil Patel using a site cover opt-in form, cleverly mixed with a quiz that any marketer would instantly want to take. The incentive here is gaining stats about the true potential of your site.

neilpatel site cover

Top bar

Top bars or floating bars stick to the top of your page. They appear as a small ribbon at the top, that doesn’t hinder the user experience and quietly sticks around until exited. They’re also implemented site-wide, ensuring that every kind of visitor will be able to notice them.

A top bar also works great for long landing pages with at least two full-screen scrolls where the call-to-action may be hard to find as you go down. This opt-in helps users to convert only when they’re ready since it stays around no matter where the user may be on the page.


  • Subtle and passive, doesn’t interrupt user scrolling
  • Good at targeting loyal customers, leading to more profit (80% of your future profit will come from just 20% of your existing customers).


  • Hard to notice so new visitors might ignore it
  • Not meant for primary lead generation

Popularly used for:

  • Latest offers, sales, updates, resources, and content upgrades

Here’s an example of a non-invasive floating bar from Minimalist Baker.

minimalist baker top bar

Embedded forms

Opt-in forms can also be embedded into a page. This subtle variant of opt-in forms is placed in the post or landing page, making it most visible to visitors that successfully engage with your content.  

Embedded forms have lots of placement options; top of the page, side panels, middle of the content, or the footer. You can choose where to embed them depending on your goal. For instance, content upgrades usually appear in the middle of a post, so users get the option to download a more comprehensive version of what they’re reading.


  • Smooth user experience, don’t interrupt readers
  • Re-engage visitors who are losing interest


  • Not ideal for primary lead generation

Popularly used for:

  • Secondary lead generation, content upgrades, resources

Have a look at one of Backlinko’s landing pages that shows an opt-in towards the end of the page, only after establishing interest in the services.


Slide-in boxes are also very popular opt-ins because of their ability to attract eyeballs without interrupting user scrolling. These slide in from the left or right side of the page, usually after a time delay to ensure visitor engagement.

The great thing about slide boxes is that they aren’t as interruptive as pop-ups or site covers but still attract sufficient attention because of the sudden movement on the page.


  • Minimal disruption to user experience while still being attention-grabbing


  • Tricky in terms of timing the delay

Popularly used for:

  • Secondary lead generation, exit intent strategy, resources

Here’s an example from Conversionxl.

cxl slide box

Testing your opt-in form types

While you’ll read a lot about opt-in form comparisons and conversion rates, nothing reveals the true picture better than A/B testing.

Different opt-in forms work for different use cases and different user types, and a lot depends on how you present them. This is why testing is the only sure way of knowing what the right kind of opt-in is for you. Here’s how to do that:

  1. Decide whether you’re targeting new or returning visitors. While aggressive opt-ins like pop-ups and site covers lure new visitors in, returning visitors will only find them annoying if they repeatedly interrupt their sessions.
  2. Choose site placement for your campaign.
  3. Start with testing the form type. You can run subsequent tests on the design and offer.
  4. Run an A/B test on the two forms you choose with your opt-in form builder.
  5. Wait for a few hundred impressions to get a sense of conversion rates for both forms.

Below we explore the various types and how you can choose opt-ins for your A/B tests.


Choosing opt-in forms can be overwhelming at times, given all the various types and use cases. But knowing your audience, the right incentive to offer, and testing will help you arrive at the perfect opt-in for the best conversion rates.

It’s also recommended that you use a handful of opt-in form types on your site; one for primary lead generation(from active opt-ins like pop-ups), and ideally two others for secondary lead generation (from passive opt-ins like embedded forms). Such a collection will help you target all kinds of visitors coming onto your site and enable you to keep them engaged with your content.

Lastly, don’t stop experimenting!

Author Bio

Momina Ayaz

Momina Ayaz is a Content Marketer at Mailmunch. She loves reading during lunch breaks and witnessing technology reshaping the corporate sphere.


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