There are plenty of ways to prevent bots from signing up to your newsletter, but most of them add friction. And friction will hurt your conversion rate. Weed out the bots without losing signups by adding a hidden field.
If bots get into your email list, they’ll mess with your metrics. Worse, you’ll send emails to bad addresses, which will hurt your sender reputation and deliverability. Luckily, there’s a super simple solution that won’t affect your site’s UX. Add an extra “email” field to your signup flow, with “display: none” in the CSS. Bots will fill out the field but humans won’t even see it. And that means you’ll know which signups are bogus so that you can remove them. It’s easy and effective against your run-of-the-mill bots. But if your site is notable enough to be targeted with a custom script, you may need to take more drastic measures.