In the age of digital advancements, as cyber threats continue to evolve, cybersecurity has become a critical component for online business. CAPTCHA, Multi-Factor Authentication (MFA), and Two-factor authentication (2FA) all play a pivotal role in the online security field, however, there is a prevalent misconception exists regarding their roles. This article will introduce their definition, and compare them to find out the inherent differences.

What is CAPTCHA?

CAPTCHA is a challenge-response test that aims to distinguish a bot from a human. Traditional CAPTCHAs ask users to input twisted texts and numbers based on the premise that humans can recognize them while bots cannot. Advanced CAPTCHAs are powered by artificial intelligence and machine learning to detect risky requests from malicious bots based on multidimensional data, including the user’s behavior trajectory, network environment, etc.

What is Multi-factor Authentication (MFA)?

Multi-factor authentication is an authentication method that gives a user access upon presenting two or more pieces of evidence to verify it’s him or her. When we talk about MFA, at least two of the following factors would be used for user authentication: 

  • something that only the user knows (knowledge-based)
  • something that only the user has (possession-based)
  • something that only the user is (inherence-based)

Multi-factor authentication usually works as the second layer of protection for the user’s account apart from ID and password. MFA helps protect users against credential stuffing attacks and account takeovers (ATOs).

What is Two-factor Authentication (2FA)?

Two-factor authentication (2FA) is a security measure in which users must provide two different authentication factors to confirm their identity and access an account or system. These factors usually involve something the user knows (like a password or PIN) and something they possess (such as a smartphone or security token). This added security layer helps thwart unauthorized access, even if one factor (like a password) is compromised.

2FA vs. MFA: What’s the difference between 2FA and MFA?

Two-factor authentication (2FA) refers to 2-step verification, requiring users to present exactly two factors for authentication for accessing an account. In most cases, they are passwords and OTP (one-time password)

Multi-factor authentication (MFA) requires a user to present at least two or more pieces of evidence, or factors, for authentication. 

Both 2FA and MFA can enhance security for user accounts beyond single-factor authentication which usually would be username and password. If you’re using passwords as the only factor to protect from unauthorized access, you should consider adding at least one more factor for authentication. 

But which one is better? 2FA or MFA? The thing you need to consider is user experience. Users won’t be happy to provide all three authentication factors. It’s better to work around a solution that allows users to select the authentication methods most convenient for them.


What's the Difference? 

The main difference between CAPTCHA and 2FA stands in the purpose. 

2FA serves to identify and authorize the user trying to commit an action that triggered 2FA, such as login into a secure account or conducting a particular action using a secure account.

For example, you need to transfer a large sum of money to a person, and a bank sends you an SMS code to verify the transaction. The main aim is to confirm that you are authorized to act. Regulations of identity authentication are kept updated.

The goal of CAPTCHA is to detect, thwart, and prevent bots from engaging in malicious activities on your website. In other words, CAPTCHA serves to protect your website or mobile apps from bot attacks. 

Can 2FA Replace CAPTCHA?

The answer is simple: 2FA and CAPTCHA cannot replace each other because their primary objectives are different.

CAPTCHAs are placed at the gateways for interaction and prevent maliciously automated computer programs from accessing and committing fraud and abuse.

2FAs are mostly placed at payment gateways or log-in for websites or apps, such as e-commerce or fintech services, to verify user identity and grant them access based on their credentials.

2FA only deals with identity verification threats, whereas CAPTCHA deals with a much wider range of automated threats. 

In other words, CAPTCHA serves to authorize access to humans only. 2FA serves to authorize access to a particular person who possesses all the necessary information to confirm their identity. Having all the necessary information for identity confirmation doesn’t always exclude being a bot.

For example, to scalp tickets for an upcoming popular event, a bot operator can register unlimited amounts of accounts while automating the 2FA process. Without an Advanced CAPTCHA, this malicious automation cannot be stopped.  


What's the Difference? 

  • Purpose: CAPTCHA verifies humans via challenges, whereas MFA boosts security with multi-factor authentication.
  • Authentication Mechanism: CAPTCHA uses challenge-response tasks, while MFA employs various authentication factors.
  • Security Level: CAPTCHA safeguards against automated attacks but lacks robust protection, while MFA notably enhances security by requiring multiple identity verifications.

Can MFA Replace CAPTCHA?

The answer is the same as 2FA, besides, conversion and privacy should be concerns since not all customers are willing to provide private information and finish the complicated authentication. 


Malicious bots make 27.7% of all internet traffic in 2021. It is the third year of a continuous increase in bad bot traffic. And among all the bad bot traffic, advanced bots are also on the rise. lt increased from 16.7% in 2020 to 25.9% of all bad bot traffic in 2021.

Whether to bolster your defenses with a 2FA or MFA depends on your business needs. 2FA or MFA will considerably impact conversion rates as well as increase the cost of customer support. The recommended approach is to deploy an Advanced CAPTCHA such as GeeTest Adaptive CAPTCHA on sensitive gateways to ensure your website can’t be maliciously automated.

GeeTest Adaptive CAPTCHA is an Advanced CAPTCHA that can secure websites and mobile apps from cyberattacks. It takes 7-layer dynamic protection and a true zero-friction approach which ensure both ease of use and security in every interaction.

Sign up for a 30-day free trial of GeeTest Adaptive CAPTCHA (credit card isn’t required)!

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Hayley Hong

Content Marketing @ GeeTest