Forms are essential for businesses looking to grow their contact database. However, they often become targets for bots that submit fraudulent information. Managing these bots and spam signups can be time-consuming and challenging, making it difficult to prioritize genuine leads. That's why protecting your forms from bots should be a top priority.

What is a form bot?

A form bot is a bot program specifically designed to fill out forms on websites. These bots autonomously navigate websites, searching for code that indicates a form field. When they find one, they populate the fields with pre-programmed data and submit it, usually with the aim of accessing restricted content, creating false subscriptions and leads, or distributing spam to website visitors and administrators. 

Why is it important to protect your forms from bots and spam signups?

Protecting forms from bots and spam signups is important for several reasons, including:

• 🧹 Keeping your email lists clean
  Bots can submit fake email addresses to your forms, leading to false subscriptions and leads. This can negatively impact your sender reputation and email deliverability, as your emails may be marked as spam more frequently and your domain could be blocklisted.
• 🚫 Preventing spam and unwanted submissions
  Bots can flood forms with spam messages, which can fill your database with irrelevant or harmful content. This makes it challenging to manage legitimate submissions and keep your system clean.
• 🌐 Improving your website experience
  Bot traffic can degrade the performance of your website, resulting in slower load times and a poor user experience. Mitigating bot traffic ensures a smoother and more responsive experience for legitimate users.

Best practices to protect your forms from bots and spam signups

Various techniques and best practices are available to protect your forms from bots and spam signups. To enhance security, we strongly recommend implementing a combination of these strategies simultaneously.

☑️ Include a CAPTCHA

A CAPTCHA is a security feature used in forms to distinguish between human users and bots. It typically presents a challenge that is easy for humans to solve but difficult for bots, such as identifying distorted text, selecting specific images, or solving simple math problems.

We recommend you always include a CAPTCHA in your forms, preferably one with a checkbox, such as the Google reCAPTCHA v2 with the "I'm not a robot" checkbox.

➡️ To learn how to add a CAPTCHA to a Brevo form, check our dedicated article Add a CAPTCHA to your subscription form.

📄 Use a double opt-in form

Unlike a single opt-in form, where users only need to provide their email address to subscribe, a double opt-in form requires an extra step of confirmation from the subscriber to confirm they want to receive your emails. Form bots can’t complete this step because the email is either fake or belongs to someone else.

➡️ To learn how to create a double opt-in form in Brevo, check our dedicated article Create a subscription form.

🍯 Add an invisible extra field or honeypot

Honeypots are invisible fields added to forms that human users cannot see or interact with, but form bots will fill in. Since legitimate users won't engage with these fields, any submission that includes data in a honeypot field can be identified and disregarded as bot-generated.

Implementing honeypots is pretty straightforward, requiring only basic HTML and CSS skills to hide the fields from human view.

⏱️ Implement a rate-limiting technique

A rate-limiting technique is applied to a form to restrict the number of submissions that can be made by a single IP address or account, usually within a specific timeframe. For instance, you might allow for one IP address to submit five times per day. Bots that quickly submit a high volume of forms will hit the rate limit and be blocked from submitting further forms.

🛠️ Use an anti-spam tool

Consider using anti-spam tools such as Akismet or WPBruiser (a WordPress plugin) on your website to eliminate form bots. These tools provide an additional layer of protection by analyzing the content of submissions and can work alongside with a CAPTCHA.

❓ Include a custom question

Protect your form by adding a simple custom question that subscribers must answer before submitting. This could be a basic question like 2+2=?. Bots often fill in fields with pre-set data, so any submission without the correct answer can be identified and dismissed as bot-generated.

🛡️ Use a web application firewall (WAF)

A web application firewall helps protect web and mobile applications from harmful web traffic and threats. It can be configured to detect and block traffic from known bot IP addresses, which can be found online and included in your firewall's blocklist.

🤔 Have a question?

If you have a question, feel free to contact our support team by creating a ticket from your account. If you don't have an account yet, you can contact us here.

If you’re looking for help with a project using Brevo, we can match you with the right certified Brevo expert partner.