If there's one thing that drives everyone nuts, it's spam, especially when it comes to running a website. One of the most common complaints new website owners have is the amount of spam comments, contact form submissions and signups that occur when your website goes live. Without some form of spam prevention, you are in for an administration nightmare. Fortunately, there are plenty of excellent options in existence and today, we're going to list out the ones we think are the best.
Website: https://cleantalk.org/
CleanTalk is a great service that offers spam protection for websites, forums, online stores and much more. The advantage is that it does not require captchas, questions or anything on the user end of things. The services checks for spam bots and spam in comments, orders, widgets, registrations, bookings, custom web forms, contact emails and much more. It works by sending the request to the cloud and using special algorithms to analyze the requests.
Website: https://akismet.com/
Akismet is the popular spam prevention plugin for WordPress by Automattic. While it's most often used on WordPress installations, a large percentage of web applications also have plugins for it. I'd recommend searching within their plugin directories to see if it's integrated with the software you are using (if you do not run WordPress).
Website: http://www.captcha.net/
While Captcha certainly isn't one of my favorite options, I have to admit that in a lot of cases, it works well. I prefer the one that simply asks you to check a box saying that you are not a robot as opposed to the sometimes difficult to read captcha's that come up on some websites. Having said that, it does work in a lot of cases otherwise it wouldn't be so widely used.
Website: https://www.mollom.com/
Mollom is a website spam filtering service similar to Cleantalk. It was originally created by Dries Buytaert (founder of Drupal) and his team and is now part of Acquia. Mollom is available for WordPress, Drupal, Radiant, SilverStripe, Java, PHP, Ruby, Python, Perl, .NET and more.
Website: http://sblam.com/en.html
Sblam! is a web service that blocks spammy posts in blog comments, forums and guestbooks (blocks bots posting adverts for viagra, porn, credit, casinos, etc.). It detects spam server-side and doesn't bother users with any puzzles to retype.
Website: http://jennamolby.com/how-to-prevent-form-spam-by-using-the-honeypot-technique/
The honeypot technique involves creating a hidden field which only spam bots will see and when they fill it out, you block the submission as normal users wouldn't see it and therefore would not fill it out. Since it's more of a technique than a web service, I've linked to an excellent tutorial I came across that explains how to implement it. Most form plugins have this ability integrated and it should be very easy to find tons of tutorials on the web if the one above doesn't suit your needs.
Did we miss one? Please let us know in the comments below. Also, if you have another method that works for you, we'd love to hear about it!