If you are like most website owners, you probably have a contact form somewhere on your website.
Unfortunately automated spam machines target contact forms and can submit dozens or even hundreds of bogus forms a day, making it very difficult to separate genuine enquiries from fake ones, and clogging up your inbox.
There are several tricks that allow us to reduce or even completely prevent automated contact form spam. Not all are suitable to every website, and it can be useful to start with the least invasive method first, and then work your way up to the more sophisticated tools if you are still receiving spam. Here's the lowdown on the most popular spam prevention methods:
Akismet - invisible and effective (but not free for businesses)
Akismet is the number 1 WordPress plugin for spam protection. It protects contact forms and also blog comments. Akismet checks your forms for spammy content and blocks them if spam is detected.
It is not perfect but pretty effective, and also does not add any ugly fields to your beautiful contact forms. However, there is a subscription fee for business websites.
reCAPTCHA v2 - a great option for most websites
reCAPTCHA's add an additional field to your contact form where people have to prove they are human. You simply click a button that says "I am not a robot", and you may need to answer a few simple picture questions. This is really easy to use and very popular.
The only downside is that it does add another field to your contact form, which may not make it suitable if you need a short form, e.g. in sidebars or footers where there is limited space.
Invisible reCAPTCHA - looks great but can block legitimate requests
The idea of invisible reCAPTCHA is that it detects if you are human without the need for additional fields in the contact form. It is invisible, except that you need an annoying little opt-in that usually floats around near your website footer.
The downside is that it can block legitimate humans trying to submit your form, and there is no way around it - not like in the "I'm not a robot" reCAPTCHA where you get another go... Invisible reCAPTCHA needs more ongoing tweaking in the backend to set it to just the right level of strictness and avoid blocking real contact form submissions by humans. This doesn't always make it practical for us to use on client websites as we can't monitor and tweak reCAPTCHA's on the 100+ websites we maintain.
For now, the "I'm not a robot" reCAPTCHA is our go-to choice for most client websites.
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