Accessibility at Hypothesis

Current Status

Hypothesis collaborates with the Inclusive Design Research Centre (IDRC) to map and improve the current accessibility status of our services. IDRC’s latest external review of Hypothesis functionality concluded that our annotation client meets WCAG 2.1 Level AA Success Criteria set out by the W3C in the Web Content Accessibility Guidelines (WCAG) 2.1. For our users in the United States of America, these criteria also meet current standards defined by Section 508 of the US Federal Rehabilitation Act and our VPAT provides more specific details about our compliance with both WCAG and Section 508 standards.

While the IDRC conducts reviews within the context of either an Instructure Canvas and/or Blackboard Learn learning management system (LMS), the functionality and accessibility issues reviewed pertain to annotation in any context, including in other LMSs and outside LMSs. Because reviews so far take place in an LMS with Hypothesis already embedded and ready to use, they do not address “Getting Started” interactions (above), which are not part of LMS use.

Our Approach

Inclusivity and availability have always been central to our mission. We’ve worked hard to design and develop Hypothesis to reduce geographic, financial, or logistical barriers to users who want to read and write annotations on the web. That’s why Hypothesis is built on open web standards, will always be free to use, and works on a wide range of formats and platforms.

We consider accessibility to be a key part of a larger effort to practice and promote what many are now calling “inclusivity.” We work to increase the accessibility of annotation through inclusive design, a practice defined by the Inclusive Design Research Centre as “design that considers the full range of human diversity with respect to ability, language, culture, gender, age and other forms of human difference.” Following inclusive design, we look to make interventions not only to support accessibility for specific types of users, but to make annotation a better and easier experience for everyone.


  • Engage with users for whom Hypothesis software has failed to provide an inclusive experience
  • Real-world testing and feedback
  • Collaboration with people and organizations that care about accessibility and inclusivity
  • Standards/guidelines compliance
  • Inclusive design as an integral part of everyday development
  • Transparency: clear, public communication about the approach, status, and plans for accessibility and inclusiveness at Hypothesis

Areas of Accessibility

Hypothesis focuses on accessibility in five general areas that together encompass the full range of interactions people have with annotation.


Hypothesis seeks to enable annotation on all web content — already including HTML web pages, PDFs and EPUBs, but with plans to expand to images, video and other formats. We recommend you consider the accessibility of the materials you make available for annotation, especially if you are asking others to participate. For example, HTML web pages are likely to be more accessible than PDFs. PDFs can be made more accessible. EPUBs may have differing levels of accessibility. Before you consider annotation, you can test the accessibility of content.

Getting Started

Enabling people to annotate privately and with others, both in environments where Hypothesis is embedded and ready to use, and using browser extensions that enable annotation across the web, including activities like:

  • Accessing Hypothesis
  • Establishing Hypothesis accounts
  • Resetting/changing passwords
  • Changing emails
  • Changing usernames

Exploring Annotations

Enabling people to find and read existing annotations, including activities like:

  • Viewing highlights
  • Viewing annotations
  • Viewing page notes
  • Viewing orphans
  • Searching annotations
  • Reordering annotations (newest, oldest, location)

Interacting with Annotations

Enabling people to engage with existing annotations, including activities like:

  • Replying to annotations
  • Sharing annotations

Creating Annotations

Enabling people to create their own annotations, including activities like:

  • Changing group context
  • Selecting text
  • Creating highlights
  • Creating annotations
  • Formatting annotations
  • Editing annotations
  • Deleting annotations

Next Steps

We continue to conduct independent reviews of our annotation software to confirm and update WCAG and other compliance.

We review and update our Vendor Product Accessibility Template (VPAT) on a regular basis to ensure it reflects accessibility-related developments.

We continue to update our website to include accessibility guidance developed in our reviews and others.

We continue to seek feedback from users who have disabilities and/or use assistive technology to ensure a good user experience rather than relying solely on compliance and “box-checking.”

Learn More and Get Involved

For details on using Hypothesis with assistive technology see the following guides:

We welcome your feedback on our approach and roadmap for accessibility and inclusivity. If you have difficulties using Hypothesis annotation and/or use assistive technology to interact with the web, we would love to hear your suggestions about how we could improve your experience. Please contact us with questions and/or suggestions. Subscribe at the bottom of this page to receive email notifications about Hypothesis and annotation, including our updates about accessibility.