How to Add Email Validation to Webflow, Wix, and Squarespace Forms

No-code builders speed up the publishing of forms. But they don't make those forms accurate.

Webflow, Wix, and Squarespace include basic email address check functionality. None of them test if the provided email address is valid, deliverable or safe to send to. That's why so many marketing lists slowly grow with addresses that will never open one email.

If you want to add email validation to forms built on these platforms, you can do it in under 10 minutes using Clearout Form Guard. This guide covers the exact steps on how to add Form Guard to each form builder.

No-code platforms verify email format but do not verify if there are any active mailboxes or if the address is for a temporary service that is going to expire in minutes.

The outcome is a CRM that can take in entries such as:

Clearout analyzed 49 million addresses on a typical unverified list, and found that only 29.31% were returned for safe delivery. The difference between "looks valid" and "is deliverable" is greater than teams realize, and every form submission that doesn't get validated is another chance for bad data.

In addition to this, email validation checks go beyond format:

All of these are not activated in Webflow forms, Wix forms and Squarespace forms.

You can add custom code using Project Settings in Webflow. A JavaScript code snippet can be inserted into the site-wide head tag for use on all pages, including the pages containing your forms.

1) In Clearout, click Create Guard.

2) Choose the fields to validate and set your rules.

3) Copy the generated snippet.

4) Paste it into Webflow forms setting.

5) Publish.

Form Guard automatically recognizes the email input field. Validation takes place real-time when a visitor enters an address and clicks on to the next field. Error message is shown in-line if the address fails. This is important because once submitted, if it is rejected, it means that it will be abandoned. Real visitors can fix typos in Inline Feedback without having to start over again.

Learn more about real-time email verification and how it helps identify invalid addresses before they enter your CRM.

To validate only specific pages, add the snippet in that page's Page Settings → Custom Code instead of Project Settings.

The custom code panel approach is cleaner for site-wide use. If you wish to only validate on one particular page, use the embed block.

Wix forms use the type of the input fields to identify them as email fields. Form Guard reads automatically in most cases and applies validation rules without manually mapping anything. If your form was created by you, make sure to verify that the field was detected prior to live on the Clearout dashboard.

Squarespace has a Code Injection area in the Advanced settings. This is the usual way to add 3rd-party scripts.

Code Injection on Squarespace will happen on all pages, meaning all forms throughout the site will be valid. Rules apply per Guard. For different requirements on different forms, create separate Guards or use custom selectors/options in the snippet.

Form Guard's 3 checks are concurrently activated: email, phone and name. All three happen as the visitor fills in the form and in real time.

Separate bot protection, in the background, with an invisible CAPTCHA. In reality, there is no additional step for the real visitors. Bots will not show anything when the challenge fails, before the form is submitted.

Form Guard will return an inline error message when a field has input.

The most common trouble or issue on marketing forms is disposable addresses. Services such as Mailinator, Guerrilla Mail and 10 Minute Mail provide addresses that are valid for just a few minutes. They even pass the format checks, since the domain is real. Form Guard's disposable detection database has thousands of known temporary mail providers.

If the mailbox has no such name, then the SMTP check will fail, but it will not be detected at the domain level. An address with a catch-all domain won't bounce right away. It might end up in an unchecked inbox or an archiving system.

Address@ is for info, support, sales, etc., not for individual users. They tend to be standard on a business contact page and are not really used for a marketing or lead nurture campaign. They are detected and flagged optionally by Form Guard, so that you can choose per campaign whether to include them or not.

Validating Webflow, Wix, and Squarespace forms with email just takes a one-snippet change and is less than 10 minutes. If you don't use Form Guard, all forms become a source of fake, disposable, and undeliverable addresses that inflate the contact count without any real pipeline.

Clearout Form Guard, the best form validation tool, seals that door at the gate. It does not let fake entries or bots enter your CRM or sequences.

The setup steps above are platform-specific and tested. Once the snippet is in, Form Guard handles the rest automatically.