In the past, solving a CAPTCHA meant identifying a set of distorted characters, selecting several images or parts of images based on specific criteria, or clicking a dedicated checkbox. We all know the process of selecting traffic lights or having to distinguish a motorcycle from a bicycle. We also know firsthand how frustrating these challenges can be for the user experience.
Companies noticed it too, and began looking for alternatives to traditional CAPTCHAs. Since the launch of Google’s reCAPTCHA v2 in 2014, so-called Invisible CAPTCHAs started to appear more and more. Invisible CAPTCHAs work with very little direct interaction from the user and use different techniques (such as behavioral analysis) to distinguish between real humans and bots in the background.
How do Invisible CAPTCHAs work?
Invisible CAPTCHAs don’t rely on the user solving a challenge or interacting with a CAPTCHA directly. Instead, they distinguish between a real user and a bot by tracking the behavior of the user (even across websites) and collecting information about them. These CAPTCHA systems can make an educated guess whether the user is human or not.
What information is tracked and collected differs between CAPTCHA systems. For example, Google is known for tracking and collecting as much information about the user as possible, which allows it to identify real humans without having to challenge them with manual CAPTCHAs in many cases. Google’s Invisible reCAPTCHA, though, comes at the price of the user’s privacy.
Other CAPTCHA providers offer a similar approach to reCAPTCHA: an Invisible CAPTCHA for enterprise customers to distinguish between real humans and bots in a basic way. These providers don’t require the user to solve any puzzle if they can collect enough data to accurately guess whether the visitor is human.
What are the benefits of Invisible CAPTCHAs?
Any break or interruption in your user’s journey on your website, however brief, negatively impacts conversions and user experience (UX). This only becomes worse when the challenge is difficult to solve, or involves several different screens. Even if the CAPTCHA challenge is relatively simple, your users may find themselves frustrated by the interruption. At the same time, allowing bots and fraudsters unhindered access to your website causes other issues that impact UX, such as poor server performance or real, concrete threats to your users, like account takeover.
Invisible CAPTCHAs were created to offer a more user-friendly solution to website protection. When a CAPTCHA doesn’t interrupt the user experience, your users are more likely to convert or purchase. They won’t become frustrated with the challenges they’re being forced to solve before completing their tasks. The more invisible your protective measures can be, the happier your users will be with your website.
Are Invisible CAPTCHAs truly invisible?
The majority of CAPTCHA providers have failed to offer truly Invisible CAPTCHAs. They appear to be invisible in many cases, but if they can’t collect enough user data or an user seems to be suspicious to them, they still require the user to manually solve a puzzle.
Common Types of “Invisible” CAPTCHAs
Most invisible CAPTCHAs involve a background verification process that can trigger additional security measures—such as CAPTCHA challenges—based on a perceived risk level. In essence, users deemed “human” by the system are considered lower risk and are unlikely to face any challenges compared to users the system thinks are bots. Some of the most well-known “invisible” CAPTCHAs include:
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Google reCAPTCHA v3: Analyzes user behavior in the background to determine whether the user is a human, providing a score between 0 and 1. The website owner then decides what to do with each score, such as triggering additional verification steps or allowing the user to proceed. With its scoring system, Google offers a relatively sophisticated tool while collecting a certain amount of information about the end user.
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hCAPTCHA: Similar to Google reCAPTCHA v3, it analyzes user behavior in the background to determine if users are human. The website owner can trigger additional verification, like a CAPTCHA challenge, for “suspicious” users.
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GeeTest: Analyzes user behavior to determine if users are human. Suspicious behavior can be met with more challenging verification, like a CAPTCHA sliding puzzle.
There are many other “invisible” CAPTCHA options on the market, such as Cloudflare Turnstile, DataDome Device Check, Arkose Labs’ FunCaptcha, HUMAN’s Human Challenge, etc. that analyze a user’s behavior and/or device. However, none of the options here are fully invisible because they challenge “suspicious” requests with a CAPTCHA or additional verification steps.
Friendly Captcha: The First Truly Invisible CAPTCHA
The only truly invisible CAPTCHA solution on the market is Friendly Captcha. Due to its cryptographic puzzle technology, Friendly Captcha never requires the user to manually solve a CAPTCHA challenge. If it suspects that a user is not a real human, it gives them a harder cryptographic puzzle which takes a longer time to solve, making automated spam prohibitively expensive. In the unlikely event that a human user is deemed suspicious, they still won’t have to solve a challenge—they will simply wait a bit longer. This makes Friendly Captcha the most accessible and user-friendly CAPTCHA solution on the market.
If you want to try Friendly Captcha for yourself, check out the live demo.
FAQ
Invisible CAPTCHAs distinguish between human users and bots by using behavioral analysis and data collection, rather than requiring users to solve a challenge. Suspicious activity, such as abnormal click behavior, is usually verified with an additional step like a CAPTCHA challenge.
Invisible CAPTCHAs reduce interruptions in a user’s journey on a website, improving the user experience and leading to higher conversion rates and happier customers. They also prevent bot-related issues such as fraud or server overload, providing protection without disrupting the user experience.
The majority of “invisible” CAPTCHAs on the market are not completely invisible. They may work in the background, but still prompt users with challenges when suspicious behavior is detected. Friendly Captcha is the only solution that is truly invisible, requiring zero manual interaction and using cryptographic puzzles when additional verification is needed.
