CAPTCHAs are all around us. At this point, most of us have accepted them as a normal everyday occurrence when using the internet. However, their use is still heavily debated by experts behind the scenes, and site owners need to weigh the pros and cons carefully before deciding to add a CAPTCHA to any part of their site’s use. While it’s true that a well-placed CAPTCHA can decrease unwanted incidents like spam and scrapers, they can also negatively impact the average user’s experience when used carelessly. Let’s take a look at some reasons why you should – and shouldn’t – use CAPTCHAs.
Pro: Improved Site Security
The main purpose of a CAPTCHA is to prevent unwanted automated access to your site. This includes various kinds of attack bots and other malicious actors, and that alone can make a CAPTCHA a great first barrier against these kinds of problems. CAPTCHAs can prevent things like DDoS attacks, which could potentially slow down your website, or even take it offline completely. This improves the overall security of the site, and any underlying systems that might be connected to it.
Pro: Decreased Spam
Another common use case for CAPTCHAs is stopping spam. This is particularly common in places like open comment fields where anyone can post without an account, private messages between users, and registration forms. Spammers trying to sign up for multiple accounts at your site will be slowed down significantly by a properly working CAPTCHA. It won’t completely stop them, and that’s definitely something you should keep in mind. But it will cut down on the number of random uncontrolled incidents severely, which is a good start.
Pro: Prevent Scraping and Other Unauthorized Usage
Having your content scraped without authorization is a common problem among site owners. There are various popular solutions to that. You can require your users to sign up for an account, or even lock certain parts of your content behind a paywall. But if you want to create as little friction as possible in the experience of your average user, simply adding a CAPTCHA in the right place(s) can do a good job at keeping most scrapers out.
Keep in mind that this might also impact how your site is indexed by search engines like Google, so adding CAPTCHAs for the specific purpose of blocking scrapers should always be done with the assistance of someone experienced.
Pro: Ensure Your Users Are Actually Human
This might seem redundant given all of the above points, but it’s something that can actually matter quite a lot on its own in some cases. Bots may not cause any negative interference in your site’s operations directly. They could be just harmlessly scraping data without overloading your servers or sending any unwanted messages.
But if you rely on tracking and metrics for optimizing your site, this kind of activity will pollute your data sets very quickly. Keeping bots out is important if you’re trying to gauge how actual users are interacting with your site in an attempt to improve it. If you don’t keep this in mind, the impact can be a lot worse than invalid data. You might actually act on that information and make changes that ruin the experience for all regular users.
Con: Annoying to Users
The biggest obvious disadvantage to using a CAPTCHA is that it’s annoying to your users. You probably don’t need any convincing of that if you use the internet on a regular basis. It’s not just about getting interrupted – sometimes, the CAPTCHA might not work correctly, leading to multiple failed attempts and a growing amount of frustration.
Or worse, you might get put on a “suspicious” list by some of your CAPTCHA providers, forcing your users to go through even more complicated checks to verify they’re human. Whether this happens is completely out of your control, and it’s often an irreversible change, at least initially.
Con: Interrupting the Site’s Use Flow
A good website should be designed for seamless, uninterrupted flow. Your users should ideally not even realize they’re clicking on any navigation elements, they’re just “in the zone” and cruising through your content. And as soon as a CAPTCHA shows up, it shatters that illusion and puts you back to square one. This might seem irrelevant in the grand scheme of things – after all, what’s a few seconds in the context of someone spending an hour or more on your site? But if you look into any in-depth user behavior analysis, you’ll find that these few seconds are often a critical breaking point for most people’s concentration.
Con: Compatibility Issues
Well-designed CAPTCHAs should work with all modern browsers out of the box. But there are some edge cases where a specific CAPTCHA, displayed on a specific page of your site under a specific browser might break the user’s ability to interact with the site in some way. It may push important content out of view, for example, or get laid over a button that the user needs to click to continue.
Uncovering these issues and addressing them is time-consuming and prone to error. Automated test suites can make that process easier, but they still don’t give you any guarantee that you’re going to catch all potential problems. You can’t even rely on your users for this purpose – most people will just close the site out of frustration when something like this happens. Your metrics might show that users drop off at that specific point, but not why it’s happening.
Con: You May Be Making Your Site Less Accessible
Last but definitely not least, you must always consider the accessibility of your site. There’s a reason good CAPTCHA providers offer workarounds, such as having the CAPTCHA read out by a voice. Something that seems simple to you might be a frustratingly difficult, even impossible, task for a person with certain disabilities. If you choose to use a CAPTCHA, you must make sure it’s tried and tested enough that it won’t lock out anyone because of their disabilities.
Adding a CAPTCHA to your site should never be a light decision. Even if it’s about one single page or point of interaction, you must think carefully about how this change is going to impact the experience of your users from as many perspectives as possible. And if you do decide to go with a CAPTCHA, try to stick to the proven solutions on the market.