CAPTCHA vs. reCAPTCHA: Why puzzle-based verification is obsolete

Introduction

Both CAPTCHA and reCAPTCHA refer to a common form of defense against bots and a wide range of nefarious online activities. But as bots have evolved, traditional puzzle-based challenges are no longer effective. Today’s advanced bots can solve CAPTCHAs better than humans, making a new approach to verification necessary.

In fact, almost 40% of all internet traffic is non-human. Spammers and cybercriminals use bots to attack platforms by slowing them down, leaving spam comments, stealing personal data, attempting brute force attacks, and committing digital ad fraud.

What is a CAPTCHA?

CAPTCHA can sound a bit complicated, especially when we’re talking about reCAPTCHA v2 vs v3. In short, CAPTCHA stands for “Completely Automated Public Turing test to tell Computers and Humans Apart”. It’s a challenge that requires internet users to pass a test to prove they’re humans, not bots, before they can continue to access a web page or platform. Since bots tend to abuse input pages, you’re most likely to find CAPTCHA tests on login pages and pages with contact forms.

Invented in 1997, just as bots, scams, and cyberattacks were beginning to pick up speed, the first CAPTCHA test was originally intended as a low-level, extra layer of security against malicious hackers and spambots (not a first line of defense). 

The original CAPTCHA test generated words that were obscured by twisted letters and slight background noise. To pass the test, users had to figure out the word and type it in. Copy/paste was not permitted, so computers had a hard time deciphering the message.

Over time, traditional CAPTCHAs have evolved to include images and varying levels of difficulty in an attempt to keep up with adapting bots, increasing their impact on the user experience. However, these evolutions have failed to keep pace with the sophistication of modern AI-powered bots.

What is a reCAPTCHA?

reCAPTCHA is a CAPTCHA system developed by scientist Luis von Ahn. It was originally released in 2007 and later acquired by Google in 2009. This security mechanism is designed to distinguish between human users and automated bots by presenting users with challenges like image identification or puzzle-solving. It typically appears as a checkbox or an interactive element on websites and, by analyzing user interactions, helps protect against spam and unauthorized activities, allowing genuine users to proceed while deterring malicious automation.

3 Types of reCAPTCHA

Since 2009, Google has introduced several different reCAPTCHA versions. Here’s everything you need to know:

1. ReCAPTCHA v1

The first version of Google’s reCAPTCHA looked a lot like the original CAPTCHAs from the late 90s. The user was given a distorted message they had to decipher to continue to the next page. Google shut down v1 of reCAPTCHA in March 2018.

2. ReCAPTCHA v2

V2 is the most common type of reCAPTCHA, still in use by many websites. V2 aims to verify legitimate interactions through:

No CAPTCHA reCAPTCHA: The user clicks on the famous “I’m not a robot” checkbox, and the risk analysis algorithm either automatically lets them through or challenges them with an image CAPTCHA (often featuring an image from Google’s massive street view library).

The Invisible reCAPTCHA badge: A company can hide the “I’m not a robot” checkbox by binding it to an existing button on its website. For example, when a user clicks on the login button, the “I’m not a robot” verification process could take place automatically. The invisible reCAPTCHA badge can also be invoked via a JavaScript API call.

3. ReCAPTCHA v3

ReCAPTCHA v3 allows users through without having to click on the “I’m not a robot” checkbox. It’s a JavaScript API behind the scenes that returns a score based on the user’s previous actions on your website, and requests further authentication if that score is close to 0.

CAPTCHA vs reCAPTCHA: Key Differences

The key difference between captcha and recaptcha is that a CAPTCHA is any website authentication test designed to tell humans and computers apart. We often refer to CAPTCHAs as reverse Turing tests because a machine administers an authentication challenge for a human to solve.

There are several types of CAPTCHAs owned by different companies/providers. ReCAPTCHA is Google’s popular CAPTCHA service, used for basic bot protection and other purposes. For example, with reCAPTCHA word tests (common before version 2 was released in 2013), Google used images from scanned books to help digitize The New York Times archives and books from Google Books.

But Google didn’t stop at digitization. Ever since image identification became a part of the tests with v2, Google has been using user input to improve its machine learning models and train its computer programs.

Limitations of Traditional CAPTCHAs for Bot Protection

50% of passed reCAPTCHAs are completed by bots, according to our aggregate customer data. Needless to say, reCAPTCHA—like other traditional CAPTCHAs—is far from infallible.

ReCAPTCHA v2, the most common version, relies heavily on cookies to work correctly, which is problematic for two reasons:

1. Users are not always willing to share their cookies and other data with Google.
2. As French regulator CNIL discovered, end-users of platforms with reCAPTCHA don’t always get presented with an option around sharing their data. That means the use of reCAPTCHA often does not comply with GDPR and similar data privacy regulations.

Privacy-conscious end-users—who often use VPNs to browse the internet and try to avoid Google services—end up having to perform multiple tests every day on websites that use reCAPTCHA v2. Ultimately, reCAPTCHA v2 kills conversions. We can’t blame users for not wanting to sort through taxis and traffic lights every time they need to submit a form.

Unfortunately, reCAPTCHA v3 tried to be more user friendly, but it introduces new challenges for site administrators who need to configure specific actions based on v3’s generated scores. Also, the popularity of reCAPTCHA gives cybercriminals more incentive and access to develop AI bots that can bypass the system.

DataDome: A Frictionless CAPTCHA Alternative for Modern Threats

At the end of the day, 50% of “users” that pass reCAPTCHAs are actually bots—a metric worth repeating. The reason? One CAPTCHA result is not enough information to accurately detect sophisticated bots.

The solution? DataDome’s specialized bot protection software blocks bots with 99.99% accuracy, ensuring the vast majority of your human users never see a verification challenge. Now, on the rare (0.01%) occasion a human does see a verification challenge, we optimize that too. DataDome uses a frictionless CAPTCHA alternative, our secure slider, to collect additional behavioral signals without frustrating users with puzzles.

Our CAPTCHA alternative is user-friendly, privacy-compliant, and secure. It can be completed by a human in about a second, a significant improvement over the time required by reCAPTCHA, and it provides a rich set of behavioral data for our detection engine.

Our verification uses a massive in-memory pattern database and a blend of AI and machine learning to determine whether a visitor is an actual user or a bot within a few milliseconds. (It’s also fast and easy to deploy—no architecture changes or DNS rerouting needed.)

ReCAPTCHA vs CAPTCHA: The Bottom Line

A CAPTCHA is a test designed to differentiate between real human users and malicious bots. ReCAPTCHA is a CAPTCHA system developed by Google.

Advanced bots threaten all websites that rely on traditional CAPTCHAs alone to keep cybercriminals at bay. Businesses can keep their platforms safe by using a comprehensive bot protection solution that uses a verification-first approach and a frictionless CAPTCHA alternative.

If you want to keep your endpoints safe while ensuring user data is private and user experience is optimized, check out DataDome’s bot management solution and our frictionless CAPTCHA alternative. Click below to book a demo.