CAPTCHAs are essential tools used on websites to provide bot protection and prevent automated software from performing actions that should only be performed by humans. While they play a critical role in improving web security, CAPTCHAs often present significant accessibility challenges, particularly for persons with different disabilities such as cognitive, visual, or hearing impairments. This article explores the critical importance of CAPTCHA accessibility as a component of overall website accessibility.

The Internet is a gateway to independence for many, but accessibility barriers can severely limit that access. According to the World Health Organization, approximately 16% of the world’s population has some form of disability. This statistic becomes even more significant in the context of Internet use, as it is estimated that 69% of the world’s population will be online by 2023 – which translates to approximately 864 million Internet users with disabilities and impairments who could face barriers due to inaccessible web design.

In regions such as the US and EU, the combined disabled population is around 25%, highlighting the need for inclusive digital spaces. Making CAPTCHA accessible not only upholds the rights of people with disabilities, but also improves the user experience, potentially increasing website conversions, improving search engine rankings, boosting brand reputation, and customer loyalty.

As we dive deeper into CAPTCHA accessibility, we will explore different types of CAPTCHAs, their specific accessibility issues, and some legal frameworks. Finally, we will compare traditional CAPTCHA providers such as hCaptcha or Google reCAPTCHA with modern CAPTCHA providers such as Friendly Captcha. This will help you master CAPTCHA accessibility and find the best accessible CAPTCHA solutions for your web project.

Accessible captcha

What is CAPTCHA Accessibility?

CAPTCHAs (Completely Automated Public Turing tests to tell Computers and Humans Apart) play a critical role in securing websites by preventing automated abuse and spam. Since traditional CAPTCHAs often require manual user interactions, such as clicking on traffic lights or cars, they present significant problems like usability and accessibility challenges for users with disabilities.

When we talk about persons with disabilities, we distinguish between the following types of different disabilities, which can be permanent, temporary, or situational: sensory disabilities, visual disabilities or vision related disabilities, auditory disabilities, and cognitive disabilities. If you apply these restrictions to the daily confrontation with CAPTCHAs on the Internet, disabled people face serious accessibility issues on several levels when solving interactive CAPTCHA challenges. In the following section, we will take a closer look at each of the five types of CAPTCHAs.

Five CAPTCHA types

Everyone knows CAPTCHAs or Completely Automated Public Turing tests to tell Computers and Humans apart. We are all familiar with some kind of interactive CAPTCHA that have to be solved manually. We’ve all searched for pictures with traffic lights, solved tricky math problems or encrypted distorted texts. There are five different types of CAPTCHAs and corresponding accessibility issues when it comes to CAPTCHA accessibility.

Text-Based CAPTCHA

Text-based CAPTCHA challenges have long been the most common type of a traditional CAPTCHA. It requires the user to enter characters embedded in a CAPTCHA to verify humans and separate bots. These CAPTCHAs come up with words, phrases, or some arbitrary combination of characters, letters, and capitalization.

To do this, the CAPTCHA presents the letters to human users in a distorted form that often requires interpretation. The distortion is achieved by warping, scaling, or rotating the characters. Sometimes graphic elements such as lines, arcs, or dots are superimposed on individual characters. This is done to eliminate bots with poor text recognition algorithms. However, this also means that persons with disabilities are too often classified as false positives.

Examples of a text-based CAPTCHA are Google reCAPTCHA v1 or smaller, unknown CAPTCHA providers. The fact that this reCAPTCHA verification method is being used less and less is a clear indication of outdated technology and accessibility issues.

Image-Based CAPTCHA

Image-based CAPTCHAs use graphic elements such as photos of traffic, animals, shapes, or scenes. The challenge of an image-based CAPTCHA is to select or identify images that match a theme. Visual CAPTCHAs were originally introduced as a replacement for a text-based CAPTCHA.

The visual challenge requires Internet users to recognize, interpret, and select from a set of images according to a given rule. Although image-based CAPTCHAs are often easier for many people to solve than text-based CAPTCHAs, these CAPTCHAs pose significant accessibility problems for visually impaired users or screen reader users. These image recognition tasks have long been difficult for bots to solve because they require both image recognition and semantic classification. As artificial intelligence improves, this advantage no longer outweighs the accessibility drawbacks.

Google’s reCAPTCHA v2 or hCaptcha are examples of image-based CAPTCHAs with visual challenges. Although the topic of accessibility in relation to these CAPTCHAs has been discussed often and for a long time, both Google reCAPTCHA v2 and hCaptcha are still in use.

Audio-Based CAPTCHA

Audio CAPTCHAs were developed as an alternative for visually impaired users to solve the accessibility problems of text-based and image-based CAPTCHAs. For blind people, solving audio-based CAPTCHA challenges or non text content is often the only way to verify that they are human.

In fact, an audio CAPTCHA is often used as a fallback to text-based or image-based methods. Audio CAPTCHAs play an audio recording that contains a specific series of letters or numbers. The visually impaired user or person with other visual disabilities must then play this back correctly.

In theory, bots should not be able to distinguish the relevant characters from unimportant background noise. However, simple computer algorithms can nowadays easily solve such audio CAPTCHA challenges. As a result, it is not bots that have significant problems with web experiences, but many humans.

Signal-Based CAPTCHA

A further development among CAPTCHAs are the so-called signal-based CAPTCHAs. The signal-based CAPTCHA tracks the user’s movements and other user activities to identify real human behavior. If the signal-based verification fails, a conventional CAPTCHA with image recognition tasks is often used.

Signal-based CAPTCHAs are often a type of invisible CAPTCHA. Instead of an interactive CAPTCHA challenge that the user has to solve manually, cookies are used to collect and store additional information and analyze behavior across sessions. This makes it possible to distinguish between human and automated behavior.

But here is the problem: Signal-based CAPTCHAs work as long as a user behaves “normally”. For persons with disabilities who rely on assistive technology or other assistive devices, this desired normality becomes a serious hurdle. The distinction between black and white, bot and human, is usually quite strict, so that any deviations are immediately sorted out. This results in a high false positive rate.

Google’s reCAPTCHA v3 is one of the most popular signal-based CAPTCHAs. However, the “No CAPTCHA reCAPTCHA” from reCAPTCHA v2 is also based on this technology and has its limitations.

Proof-of-Work CAPTCHA

A proof-of-work CAPTCHA uses a cryptographic puzzle that is solved by the user’s device with some computational effort. Modern proof-of-work CAPTCHAs additionally evaluate advanced risk signals to adapt the difficulty level of the cryptographic puzzles based on risk assessment.

A proof-of-work CAPTCHA is essentially an invisible CAPTCHA that does not require image, text, or audio CAPTCHAs, or any other CAPTCHA challenge. There is no need for humans to perform any tasks manually, as the device does this in the background. While the user is filling out a web form, the CAPTCHA puzzle is solved invisibly and within a few seconds.

The combination of a cryptographic puzzle and advanced risk signals allows for accurate analysis of user behavior, ensuring a high level of website security. From an accessibility perspective, a proof-of-work CAPTCHA is completely barrier-free, as there are no manual challenges to solve.

The pioneer of advanced Proof-of-Work CAPTCHAs is Friendly Captcha. This barrier-free CAPTCHA provider not only ensures optimal bot protection, but is also accessible without CAPTCHA challenges, WCAG compliant, and GDPR compliant.

Accessibility Issues with CAPTCHAs

As we have seen, there have been many developments in the past that claim to make CAPTCHAs more accessible and easier to use. However, there is still a growing need for innovative technology that does not challenge users and does not create additional barriers. A proof-of-work CAPTCHA seems to meet all the requirements for high bot protection and high accessibility. However, until we reach this stage everywhere, there will still be a large number of accessibility issues with traditional CAPTCHAs.

For example, people with visual impairments often find it difficult or impossible to decipher picture or text puzzles, as seen in traditional image-based approaches. As screen reader users, they rely on assistive technology or major screen readers, which in many cases do not correctly reproduce the visual CAPTCHA tests. These tests primarily affect blind people, but can also occur temporarily when glasses are misplaced or when sunlight on the screen is distracting.

Or people with cognitive and other visual disabilities, or the elderly, may have difficulty completing complex CAPTCHA tests as instructed. Using inaccessible traditional CAPTCHAs can therefore discourage people with temporary cognitive impairments, such as migraine sufferers, from using web forms. People with sensory impairments, such as having an arm in a cast, can be excluded from using traditional CAPTCHAs because they cannot select the correct fields in image recognition tasks.

In general, traditional CAPTCHAs often assume that all Internet users can read and even transcribe English words and characters. This means that a large number of non-English speaking Internet users may not be able to solve the CAPTCHA test.

In contrast, modern CAPTCHA solutions run completely in the background, using a proof-of-work mechanism and risk signal evaluation to ensure that they are always fully accessible. An accessible CAPTCHA solution opens up inclusive web space and online services to everyone without any barriers. As a website operator, you can achieve this inclusiveness by complying with international accessibility laws and frameworks such as WCAG or EAA.

In the following section, we will look at the legal requirements to master CAPTCHA accessibility and website accessibility in general.

Overcoming accessibility hurdles

Accessibility Compliance: Legal and Regulatory Framework

When it comes to an accessible CAPTCHA solution, many providers fall short of accessibility compliance. Visual CAPTCHAs with text or images exclude visually impaired people using major screen readers, audio CAPTCHAs are equally difficult to solve, and signal-based CAPTCHAs collect too much data only to end up asking for image recognition tasks again.

There are legal requirements and frameworks with international and national standards to follow for CAPTCHA accessibility in the context of broader website accessibility. For example, the Deque University provides a CAPTCHA accessibility checklist according to the WCAG guidelines. The checklist states that traditional CAPTCHAs should be avoided whenever possible. Instead, use intelligent algorithms, such as proof-of-work, that do not rely on human input.

Some guidelines are legally binding in certain areas, such as the European Accessibility Act. Its requirements – including accessibility compliant CAPTCHAs – will be mandatory for all companies based in Europe or with European customers by June 2025.

CAPTCHA and Web Content Accessibility Guidelines (WCAG)

The Web Content Accessibility Guidelines are an international standard that provides a set of recommendations for making web content more accessible. The WCAG includes versions WCAG 2.0 from 2008, WCAG 2.1 from 2018, and WCAG 2.2 from 2023. The WCAG technical documents are produced by the Working Group on Accessibility Guidelines (WG) as part of the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C).

The WCAG consists of 13 guidelines, each of which falls under four principles: “perceivable, usable, understandable, and robust”. Each guideline is tested against defined success criteria. These are divided into three levels: A, AA, and AAA.

Within the W3C group, there is a draft note on the “Inaccessibility of CAPTCHAs“. It discusses the challenges of CAPTCHA accessibility for all people and alternative forms of visual turing testing on the Web. In general, visual turing tests, such as an interactive CAPTCHA challenge, are acceptable under WCAG if very specific requirements are met. To use a WCAG compliant CAPTCHA, the following requirements must be met:

  • There must be a presentation with alternative output modes for all types of sensory perception.

  • There must also be text alternatives that are easier to understand for the text describing the CAPTCHA and its purpose.

In summary, traditional CAPTCHAs are acceptable under the Web Content Accessibility Guidelines as long as they implement the requirements. For example, an image recognition CAPTCHA must provide an audio alternative. Once these restrictions are met, the security of the CAPTCHA is compromised. It can be easily solved by bots and still be difficult for people with disabilities. This makes it difficult for website operators and administrators to use traditional CAPTCHAs while ensuring accessibility.

CAPTCHA Compliance in the EU and European Accessibility Act (EAA)

The European Accessibility Act is a major legislative initiative that aims to improve accessibility across a range of digital and physical products and services. Based on the principles of the 2008 UN Convention on the Rights of Persons with Disabilities, the EAA aims to ensure that everyone, including people with disabilities, can access new technologies and services. Introduced as EU Directive 2019/882, it reflects a growing international commitment to digital accessibility, initially targeting public online services but increasingly focusing on the private sector.

By the directive’s full application date of June 28, 2025, the EAA will mandate accessibility standards and CAPTCHA accessibility in areas as diverse as e-commerce, smartphones, computers, ATMs, transportation services, and banking, among others. The EAA introduces strict regulations to ensure that digital devices and products are accessible to all users, especially those with disabilities.

These standards are critical in countries where accessibility requirements may vary, ensuring a consistent approach across the EU. The directive applies to all companies that provide the covered products and services within the EU, impacting businesses regardless of where they are headquartered as long as they serve European customers.

Although the EAA specifies general accessibility requirements, it does not prescribe any specific technical solutions, such as for accessible CAPTCHAs. Instead, the EAA follows the Web Content Accessibility Guidelines, which provide detailed technical guidelines for achieving accessibility and specifically CAPTCHA accessibility. With different output modes for all types of disabilities (such as an audio CAPTCHA as a fallback for an image recognition test) and alternative text for all types in the CAPTCHA environment, a CAPTCHA can be made accessible. However, combining several types of traditional CAPTCHAs can lead to security holes that often render such setups useless. Therefore, modern CAPTCHAs based on proof-of-work are a state-of-the-art alternative to open a barrier-free access to websites while ensuring security.

In preparation for the EAA in 2025, it is critical for CAPTCHA developers and website administrators to continually seek and implement CAPTCHA solutions that respect and enhance the user experience for everyone. By complying with the EAA and other legal frameworks, companies not only avoid the legal consequences of non-compliance, but also make a positive contribution to creating an inclusive digital environment that values all users equally.

CAPTCHA Accessibility and Section 508 of the Rehabilitation Act

Section 508 of the Rehabilitation Act is a key U.S. federal law that mandates accessibility in all electronic and information technology (EIT) developed, procured, maintained, or used by the federal government. Originally enacted in 1973 and significantly amended in 1998 to emphasize this technology focus, Section 508 ensures that people with disabilities have comparable access to and use of information and data that mirrors the experience of people without disabilities, unless meeting these standards would result in an undue burden.

Crucially, Section 508 incorporates the Web Content Accessibility Guidelines, which include specific requirements for CAPTCHAs – an automated public Turing test designed to distinguish human users from bots. According to these guidelines, CAPTCHAs must be accessible to people with visual, auditory, motor, or cognitive disabilities. This includes providing alternative modalities for solving CAPTCHAs and ensuring that if one modality (such as a visual challenge) proves inaccessible to a user, an alternative (such as an audio CAPTCHA) must be available. Website administrators and operators who don’t want to worry about the WCAG requirements for CAPTCHAs rely on modern CAPTCHAs such as proof-of-work CAPTCHAs. By solving the cryptographic background puzzles, only bots are challenged, not humans.

By aligning with WCAG, Section 508 promotes an accessible digital environment and ensures that security measures such as CAPTCHAs do not exclude people with disabilities from fully participating in the digital age.

Accessible CAPTCHAs and Americans with Disabilities Act (ADA)

The Americans with Disabilities Act is a fundamental civil rights law enacted in the United States in 1990 to protect people with disabilities from discrimination and to ensure their full participation in society. This sweeping legislation covers several areas, including employment, transportation, public accommodations, communications, and access to state and local government programs and services.

One critical aspect of the ADA that has gained prominence in the digital age is web accessibility and CAPTCHA accessibility. Although the ADA does not specifically mention online environments or CAPTCHAs, legal interpretations and court rulings have increasingly recognized websites as extensions of public accommodations.

In particular, the ADA’s impact on web accessibility has encouraged the adoption of the Web Content Accessibility Guidelines as a framework for compliance. This includes ensuring that security and verification tools, such as CAPTCHAs, are accessible. Under the ADA, CAPTCHAs and other interactive elements must provide alternative options that accommodate a range of disabilities to ensure that no individual is prevented from accessing necessary services or information online. However, these alternative modes and text alternatives for traditional CAPTCHAs provide an additional target for bots.

Simple bots can quickly solve audio CAPTCHA alternatives as an option to image recognition tasks. For real humans, this can be another hurdle, as they may not be native speakers or be able to successfully filter out the distractiADng background noise. In the end, the only people left out are the humans.

For this reason, the selection of an appropriate CAPTCHA must take accessibility issues seriously. Modern CAPTCHA solutions that use a proof-of-work approach combined with advanced risk signals are the right choice for unrestricted accessibility in compliance with the ADA.

By requiring that digital content and security measures such as CAPTCHAs be accessible, the ADA not only promotes inclusivity, but also pushes organizations to adopt universal design principles that benefit all users. This approach underscores the ADA’s role in promoting an accessible and inclusive digital landscape and reflects its historic commitment to improving website accessibility and CAPTCHA accessibility for all people.

Barrier-Free CAPTCHA and Accessibility for Ontarians with Disabilities Act (AODA)

The Accessibility for Ontarians with Disabilities Act is an innovative legislative framework enacted in 2005 in Ontario, Canada, with the goal of creating a fully accessible province by 2025. This comprehensive legislation requires all organizations in the public, private and non-profit sectors to meet various accessibility standards in areas such as customer service, employment, information and communication, transportation and the built environment.

A key component of the AODA relates to information and communication, specifically digital accessibility. The law requires all web content to be WCAG-compliant, making it easier for persons with disabilities to access web-based resources and services. This includes ensuring that security features, such as CAPTCHAs, used on websites are also fully accessible.

Under the AODA, CAPTCHAs must provide alternatives that accommodate users with a range of disabilities, including visual, hearing, motor impairments or cognitive disability. For CAPTCHAs, this means: According to the AODA, a visual CAPTCHA must have an audio challenge. At the same time, CAPTCHAs based on an audio challenge must have a visual or text alternative so that no one is excluded from accessing essential digital functionality. An even better solution is modern proof-of-work CAPTCHAs, which have been welcomed by users with disabilities.

By mandating such inclusive practices, the AODA not only advances the rights of persons with disabilities, but also sets a precedent for accessibility that impacts the global discourse on digital inclusion. It emphasizes that CAPTCHA accessibility is not just a matter of WCAG compliance, but a fundamental aspect of user experience that improves digital interaction for everyone.

In the next section, we will look at traditional current CAPTCHA methods, new modern solutions, and how they affect CAPTCHA accessibility.

Evaluating Accessible CAPTCHA Solutions and CAPTCHA Accessibility Issues

So far we have seen that there are different types of CAPTCHAs. In particular, we distinguish between traditional CAPTCHAs and modern CAPTCHAs. We also gained an overview of global legal requirements and saw that the issue of CAPTCHA accessibility is becoming an increasingly important part of website accessibility.

Now we will look at the accessibility aspects of popular CAPTCHA solutions such as hCaptcha, Google reCAPTCHA and Friendly Captcha and compare their effectiveness in ensuring security and CAPTCHA accessibility. Our goal is to determine the extent to which these CAPTCHA systems comply with legal standards and to evaluate their overall usability for users with different disabilities. By comparing these systems, we aim to highlight the strengths and limitations of each system and provide insights that can help web developers and content creators choose the most appropriate and accessible CAPTCHA solution for their needs.

hCaptcha Accessibility

hCaptcha is a CAPTCHA system designed to protect websites from bots while allowing human users to pass. However, its accessibility features and the implementation of these features deserve a closer look to understand how they serve users with disabilities.

hCaptcha typically uses image-based CAPTCHAs or tests that ask users to identify objects in images. For people with visual impairments, these visual Turing tests can be very challenging. The visual challenges are also difficult to solve when alternative text is provided, as the context and nuances of images are difficult to convey through text alone.

Since the hCaptcha provider Intuition Machines seems to have recognized the accessibility issues with their CAPTCHA, there is a way to bypass these CAPTCHA tests. Users looking for an accessible version of hCaptcha have to navigate to a special ULR and go through a registration process. This step itself may be an accessibility barrier for persons with impairments. Once registered, hCaptcha provides a cookie that recognizes users with disabilities on all sites that use hCaptcha without performing a CAPTCHA test.

The use of a persistent cookie raises privacy concerns because it tracks the user’s web activity across all sites using hCaptcha. Users must therefore weigh their need for easier access against their right to privacy. The two must never be pitted against each other. Also, this authentication method relies heavily on the user’s ability to manage and maintain cookies on their device, which may not be feasible for all users.

In summary, the effectiveness of the automated public Turing test as a security measure is called into question if pre-registration allows human users to bypass the hCaptcha. While this approach removes barriers to accessibility, it also potentially weakens the main function of the CAPTCHA – distinguishing between human users and bots. This trade-off highlights a critical issue in the design of hCaptcha: the balance between security and accessibility is often difficult to achieve without sacrificing one for the other.

Although hCaptcha attempts to improve accessibility by offering the option to register, this solution has significant drawbacks. The requirement to register for easier access and the resulting privacy concerns, combined with the potential reduction in security effectiveness, pose serious challenges for users and developers alike. As CAPTCHA technology continues to evolve, finding an hCaptcha alternative that ensures both robust security and true accessibility remains a far-reaching decision.

Google reCAPTCHA Accessibility

Google reCAPTCHA is one of the most popular CAPTCHA systems. There are two versions: reCAPTCHA v2 and reCAPTCHA v3. Despite its widespread use, the accessibility of the different versions of reCAPTCHA raises several concerns, particularly regarding compliance with the Web Content Accessibility Guidelines (WCAG).

Google’s reCAPTCHA v2 typically requires users to identify and select specific images from a grid based on a text prompt. This visual challenge is inherently inaccessible to users who are blind or have low vision, as it relies entirely on the ability to see and interpret visual content. Due to WCAG guidelines, reCAPTCHA v2 offers alternative forms such as an audio CAPTCHA alternative and text alternatives. You can find a complex Google support page about the accessibility of reCAPTCHA v2 and how to solve the audio challenge. Understanding this page can be another barrier for many users with disabilities.

CAPTCHA reCAPTCHA v3 is the latest version of reCAPTCHA verification. Using a behavioral analysis approach, it tries to work mostly in the background and be invisible. It assigns a score to each user interaction based on the likelihood that the user is a bot. This score-based system minimizes user interaction, potentially increasing accessibility by eliminating the need to solve traditional image-based CAPTCHAs.

The reCAPTCHA verification remains invisible to users unless their activities trigger a risk flag, at which point an additional interactive CAPTCHA challenge may be presented. These risk flags can affect people with disabilities who are dependent on aids or assistive technology, for example. The reliance on “normal” user behavior can inadvertently exclude or penalize users with disabilities, contradicting the core principles of accessibility and inclusivity that are supposed to be upheld under WCAG.

However, the method of tracking user interactions to generate a behavior score raises privacy concerns. The reCAPTCHA v3 cookies store extensive data about the user’s engagement with the site, which could violate on personal privacy.

Google is doing its best to make reCAPTCHA WCAG compliant. However, real-world use and user feedback suggest that reCAPTCHA verification may not fully meet these accessibility standards. To learn more about accessibility with reCAPTCHA, you may want to take a look at the Google reCAPTCHA help center. In response to the question “This CAPTCHA is too hard“, users received the following response, which could be interpreted as ironic: “Don’t worry. Some CAPTCHAs are difficult. Just click the reload button next to the image to get another one.” There are alternatives to reCAPTCHA that take the concerns of all humans, including those with disabilities, seriously and allow for inclusive online access for everyone.

Friendly Captcha Accessibility

Friendly Captcha is emerging as a modern CAPTCHA solution in the field of bot protection, designed to verify user authenticity without compromising accessibility or privacy. Friendly Captcha takes a different approach from traditional CAPTCHAs by using proof-of-work technology that automates the verification process and eliminates the need for human interaction with challenge-response testing.

Friendly Captcha is designed with accessibility in mind. Unlike hCaptcha or reCAPTCHA, Friendly Captcha is an invisible CAPTCHA that works completely in the background, processing security checks without requiring any manual user input. By eliminating the need for interactive challenges, the modern, proof-of-work-based CAPTCHA alternative avoids common accessibility issues and barriers associated with traditional image-based CAPTCHAs or text-based CAPTCHA challenges.

This feature is particularly beneficial for users with disabilities who may find typical CAPTCHA tasks, such as image recognition or audio transcription, difficult or impossible to complete. This verification method significantly improves accessibility and ensures that Friendly Captcha is fully compliant with WCAG guidelines.

But how does Friendly Captcha’s proof-of-work technology work? The core technology behind Friendly Captcha is a sophisticated proof-of-work algorithm. Friendly Captcha generates a cryptographic, invisible puzzle that is solved in the background by the user’s device. To distinguish between computers and humans, the puzzles are combined with advanced risk signals and difficulty scaling to provide the best bot protection, spam protection, and spam prevention.

Friendly Captcha is an example of how to implement security measures without forcing users to compromise between privacy and accessibility. It manages web security without HTTP cookies or persistent browser storage. As a result, it provides easy compliance with privacy laws such as GDPR or CCPA.

Websites that use Friendly Captcha are likely to see improved user satisfaction, as visitors are not subjected to intrusive or challenging tests. This user-friendly approach can contribute to higher engagement and trust from users who value accessibility and privacy.

In summary, Friendly Captcha stands out as a forward-thinking solution that addresses the traditional pitfalls of web security and CAPTCHA accessibility issues. Its compliance with WCAG and GDPR, combined with the use of latest proof-of-work technology, sets a new standard for an accessible, private and user-friendly CAPTCHA solution. By integrating Friendly Captcha, websites can provide a more inclusive environment that respects both the accessibility needs and privacy rights of all users.

CAPTCHA Type Text-based Image-based Audio-based Signal-based Proof-of-Work
reCAPTCHA v2, hCaptcha
Friendly Captcha
Visual Impairment Accessibility
very low
very low
Auditory Impairment Accessibility
very low
Cognitive Impairment Accessibility
Compliance with WCAG
no compliance
no compliance
no compliance
partial compliance
full compliance
Additional Notes
often relies on distorted text that can be challenging for visually impaired users; fallback needed
requires visual discernment of images, which can be inaccessible to blind users; fallback needed
difficult for users with hearing impairments; relies on the ability to hear and interpret distorted audio; fallback needed
analyzing signals and user interaction patterns; can be accessible, but false positive judgments are possible
no user interaction required and works in the background

Conclusion: Is CAPTCHA accessible?

CAPTCHAs are critical for bot protection by preventing automated actions, but they often pose significant accessibility challenges, especially for people with disabilities. Approximately 16% of the world’s population has some form of disability, highlighting the need for inclusive web design, especially as Internet usage grows. Different types of traditional CAPTCHAs, including text-based, image-based, audio-based, or signal-based CAPTCHAs, each present unique accessibility issues. Modern solutions such as proof-of-work CAPTCHAs provide greater accessibility by eliminating manual challenges. Regulatory frameworks such as WCAG, EAA, Section 508, ADA and AODA rightly mandate accessible CAPTCHA solutions to ensure inclusivity and compliance with accessibility standards.

As we’ve explored the offerings of the major CAPTCHA providers hCaptcha vs. Google’s reCAPTCHA, and Friendly Captcha, it’s clear that each provider has taken different approaches to balancing these critical aspects – with varying degrees of success in making CAPTCHA accessible and ensuring compliance with global standards:

  • hCaptcha: While hCaptcha blocks bots and provides a way for site owners to generate revenue, its CAPTCHA accessibility features for users with disabilities demand prior registration. This can create barriers to spontaneous access and raises privacy concerns due to its reliance on cookies. Although hCaptcha attempts to address visual challenges, requiring users to actively solve these puzzles can be a barrier, especially for those with disabilities and elderly people.

  • reCAPTCHA: Google’s reCAPTCHA, especially in version 3, appears to be a slight improvement in accessibility. reCAPTCHA v3, which makes decisions based on signals and user behavior analysis, reduces the barrier for users, but not without concerns. This system could inadvertently flag users with assistive needs as atypical, leading to potential false positives. In addition, previous versions such as reCAPTCHA v2, while offering audio and visual challenges, remain partially inaccessible to users with certain disabilities. In addition, the use of Google’s reCAPTCHA with the use of cookies is particularly critical from a data protection perspective.

  • Friendly Captcha: Friendly Captcha is proving to be the most innovative provider in terms of accessibility and privacy. By using proof-of-work technology that works in the background without requiring user interaction, Friendly Captcha removes significant accessibility barriers for people with disabilities. Its design not only adheres to WCAG guidelines, but also respects data protection principles, making it an exemplary model for future CAPTCHA technologies that prioritize user experience alongside robust security measures.

Moving Forward in CAPTCHA Technology

The evaluation of these CAPTCHA providers highlights a pivotal shift in the way digital security measures are being designed, with a greater focus on CAPTCHA accessibility and user privacy. While no system is without its flaws, the move towards more accessible CAPTCHA examples such as Friendly Captcha represents a significant step forward in making the Internet more accessible to all users, regardless of ability.

We have seen that the security of traditional CAPTCHAs can be compromised when using outdated fallback solutions such as audio CAPTCHAs in an attempt to comply with WCAG standards. Different output modes for different disabilities and alternative text for all content in the CAPTCHA environment make traditional CAPTCHAs more accessible at first glance – but also to bots. Modern solutions such as proof-of-work CAPTCHAs take a different approach, where you don’t have to worry about these requirements.

The journey to fully accessible CAPTCHAs is ongoing, and the lessons learned from evaluating these vendors can guide further advancements in CAPTCHA technology, ensuring that security does not come at the expense of accessibility. Try Friendly Captcha for yourself to experience a truly accessible CAPTCHA solution. Watch the live demo or create a free trial account.



In general, visual Turing tests like Google’s reCAPTCHA are allowed under the Web Content Accessibility Guidelines (WCAG) – but with some restrictions. For example, sites using reCAPTCHA must provide different “output modes for different types of sensory perception”. In addition, alternative text is required that further describes and identifies the purpose of the non-text content, such as the text explaining the CAPTCHA challenge.

If you are looking for a CAPTCHA alternatives without any restrictions and with full WCAG compliance, you will find the right solution in Friendly Captcha.

CAPTCHA accessibility varies by provider and integration. Traditional CAPTCHAs such as reCAPTCHA v2 or hCaptcha can pose significant barriers for people with disabilities. In contrast, modern CAPTCHA technologies such as Friendly Captcha are more inclusive by providing invisible background challenges on a proof-of-work basis.

Traditional CAPTCHAs such as hCaptcha or reCAPTCHA address accessibility by providing features such as audio fallback versions for the visually impaired, ensuring compatibility with screen readers, or bypassing the CAPTCHA through a manual registration process and cookies.

On the way to a more user-friendly CAPTCHA, Friendly Captcha offers a modern approach: With its proof-of- work technology, it is truly invisible and challenges multiple devices, not human users. By never requiring a human to manually solve a CAPTCHA challenge, Friendly Captcha literally eliminates accessibility issues.

Yes, there are accessible alternatives to CAPTCHA, such as honeypot methods, time-based heuristics, or the implementation of biometrics. While these alternatives may improve accessibility, they can only provide limited web security. Barrier-free CAPTCHA alternatives like Friendly Captcha provide maximum security and accessibility at the same time. Friendly Captcha is the accessible alternative to traditional CAPTCHAs such as reCAPTCHA or hCaptcha.