What’s the Difference Between Single and Double Opt-in?

There are different reasons you may want to use single opt-in or double opt-in for subscribing leads.

In this article, you’ll learn the difference between double and single opt-in and how to configure both for your email service provider.

Before You Start

Single opt-in is when a visitor submits their email address and they are immediately added to the email list and can begin receiving emails you send.

Double opt-in is when a visitor needs to confirm their email by selecting a link in an email they receive before they are added to your mailing list.

Pros and Cons

Single Opt-In

Pros of using single opt-in

• All leads are added to your list immediately.
• Because they are added immediately you can begin delivering content to them more quickly.

Cons of using single opt-in

• You may end up with more low-quality leads.
• Your list can contain incorrectly typed or fake emails. Having types of leads in your list can affect how accurate the email open rate reports are for your email campaigns.
• Based upon GetResponse’s findings, you can have better overall email marketings stats by using double opt-in instead of using single opt-in.

Double Opt-In

Pros

• Leads are typically higher-quality and result in a better email open rate for your email campaigns.
• No mistyped or fake emails are added to your list because a valid email is required before the lead can confirm their subscription.
• A healthier email list that gives you more accurate statistics.

Cons

• Possible that the lead forgets to confirm their subscription, or the confirmation email ends up in their spam folder.

Which solution works best for you depends on your business plan and marketing strategy. There is no perfect hard and fast rule.

For more details and tips on which you should use, see our article Double Opt-In vs. Single Opt-In: Which Is Better for Conversions?

ESP Default Settings

Updated January 23, 2025.

Because the default opt-in settings are different for each Email Service Provider (ESP), we’ve outlined a quick reference for each of the ESPs we natively integrate with.

ActiveCampaign

ActiveCampaign uses double opt-in by default. Use our custom HTML integration to change your list to single opt-in by following ActiveCampaign’s guide.

AWeber

AWeber uses double opt-in by default. Use our custom HTML integration to change your list to single opt-in by following Aweber’s guide.

Bento

Bento uses single opt-in by default. You can use our custom HTML integration to change your list to double opt-in by following Bento’s guide.

Brevo (formerly Sendinblue)

Brevo uses single opt-in by default. You can use our custom HTML integration to change your list to double opt-in by following Brevo’s guide.

Campaign Monitor

Campaign Monitor uses double opt-in by default. Use our custom HTML integration to change your list to single opt-in by following Campaign Monitor’s guide.

Constant Contact

Constant Contact uses single opt-in by default. Use our custom HTML integration to change your list to double opt-in by following Constant Contact’s guide.

CM Commerce

CM Commerce uses double opt-in by default. Use our custom HTML integration to change your list to single opt-in by following Campaign Monitor’s guide.

Customer.io

Customer.io uses single opt-in by default. Use our custom HTML integration to change your list to double opt-in by following Customer.io’s Guide

DotDigital

DotDigital uses double opt-in by default. You can disable double opt-in by following our guide here.

Drip

Drip uses single opt-in by default. You can still use our native integration but change your list to double opt-in by following Drip’s guide.

Eloqua

Eloqua uses single opt-in by default. Use our custom HTML integration to change your list to double opt-in by following Eloqua’s guide.

EmailOctopus

EmailOctopus uses single opt-in by default. You can still use our native integration but change your list to double opt-in by disabling the subscribe automatically setting in the Lead Options.

Emma

Emma uses single opt-in by default. You can use our custom HTML integration to change your list to double opt-in by following Emma’s guide.

Feedblitz

Feedblitz uses double opt-in by default and released a beta program for eligible users to enable single opt-in.

Feedburner

Feedburner uses double opt-in by default and does not allow single opt-in.

GetResponse

GetResponse uses single opt-in by default. You can still use our native integration but change your list to double opt-in by following GetResponse’s guide.

HubSpot

HubSpot uses single opt-in by default. You can still use our native integration and change your list to double opt-in by following Hubspot’s guide.

iContact

iContact uses single opt-in by default. You can still use our native integration and change your list to double opt-in by following iContact’s guide.

iPost

iPost uses single opt-in by default and provides no documentation for enabling double opt-in.

Keap (InfusionSoft)

Keap (InfusionSoft) uses single opt-in by default. You can still use our native integration and change your list to double opt-in by following Keap’s guide.

Kit (formerly ConvertKit)

Kit uses double opt-in by default. Use our custom HTML integration to change your list to single opt-in by following Kit’s guide.

Klaviyo

Klaviyo uses double opt-in by default. You can still use our native integration and change your list to single opt-in by contacting Klaviyo and following Klaviyo’s guide.

MailChimp

MailChimp uses double opt-in by default. You can disable double opt-in by following our guide here.

MailerLite

MailerLite uses double opt-in by default. You can use our custom HTML integration and change your list to single opt-in by following MailerLite’s guide.

MailPoet (Wysija)

MailPoet (Wysija) uses double opt-in by default. You can still use our native integration and change your list to single opt-in by following MailPoet’s guide.

Marketing Cloud Account Engagement

Marketing Cloud Account Engagement uses single opt-in by default. You can still use our native integration and change your list to double opt-in by following Marketing Cloud Account Engagement’s guide.

Marketo

Marketo uses single opt-in by default. You can use our custom HTML integration and change your list to double opt-in by following Marketo’s guide.

OmniSend

OmniSend uses single opt-in by default. You can use our custom HTML integration to change your list to double opt-in by following OmniSend’s guide.

Ontraport

Ontraport uses single opt-in by default. You can use our custom HTML integration to change your list to double opt-in by following Ontraport’s guide.

SendPulse

SendPulse uses single opt-in by default. You can still use our native integration and change your list to double opt-in by following our guide here.

SharpSpring

SharpSpring uses single opt-in by default. You should be able to use our custom HTML integration to change your list to double opt-in. We recommend reaching out to SharpSpring support for instructions on setting your form embed code to use double opt-in.

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