Accessibility problems in online courses are not always dramatic. Sometimes they are hiding in plain sight: a heading that is really just bold text, a link labeled "click here," an image with no alternative text, or a video students cannot fully use without hearing the audio. Individually, these issues may seem small, but together they can create a learning environment filled with unnecessary barriers.
The good news is that many common accessibility problems are preventable. Instructional designers and instructors do not need to become accessibility engineers overnight to make meaningful improvements. They do, however, need to understand how everyday course design decisions affect learners who use screen readers, keyboards, captions, magnification, voice recognition, and other assistive technologies.
Accessible design is also not something we should save for the final course review. It works best when accessibility is considered while content is being created, selected, and organized. In this article, we will look at some of the most common accessibility mistakes found in online courses and practical ways to avoid them.
Mistake #1: Using Visual Formatting Instead of Real Headings
A course page may look beautifully organized to a sighted learner while having almost no meaningful structure for someone using assistive technology. One common reason is that instructors create "headings" by making text larger, bold, or a different color instead of applying actual heading styles.
True headings provide structural information. They help screen reader users understand how sections relate to one another and allow learners to navigate directly between sections rather than reading everything from beginning to end.
Headings should also follow a logical hierarchy. A primary section might use Heading 2, with subsections underneath using Heading 3 rather than jumping unpredictably between heading levels. The goal is not simply making the page look organized but building organization into the underlying structure.
This is one of those accessibility improvements that also benefits everyone. A well-structured page is easier to scan, navigate, and understand, regardless of which technology a learner uses.
Mistake #2: Forgetting Alternative Text
Images can communicate information quickly, but learners who cannot see an image need another way to understand its purpose.
Meaningful images should include alternative text, commonly called alt text. Effective alt text communicates the information or function of the image rather than attempting to describe every visible detail.
For example, imagine a course includes a graph showing enrollment increasing steadily over five years. Alt text such as "graph" does not communicate anything useful. Something like "Line graph showing enrollment increasing each year from 2022 through 2026" gives the learner the information the image was intended to convey.
Decorative images are different. If an image contributes no instructional information, it should generally be identified as decorative so assistive technology can skip it. Not every picture needs a miniature essay attached to it.
Context matters when writing alt text. Ask yourself what information a learner needs from the image to understand the surrounding content.
Mistake #3: Relying on Color Alone
Color is an excellent design tool, but it should not be the only way information is communicated.
Consider instructions such as:
"Items highlighted in red are required. Items highlighted in green are optional."
A learner who cannot distinguish those colors may miss the distinction entirely.
Instead, combine color with another indicator. Labels, icons, patterns, text, or symbols can communicate the same information without requiring learners to perceive color differences.
For example:
Required: Submit the research proposal.
Optional: Complete the additional practice activity.
Color can still reinforce the difference visually, but it no longer carries the entire instructional message.
Mistake #4: Using Poor Color Contrast
Another common problem occurs when text and background colors do not provide enough contrast.
Light gray text on a white background may look elegant in a design mockup, but elegance becomes considerably less impressive if learners cannot comfortably read it. The same problem can occur with text placed over photographs, patterned backgrounds, or brightly colored graphics.
Sufficient color contrast supports learners with low vision, color vision differences, aging-related vision changes, and learners viewing content under less-than-ideal conditions. Even someone trying to read a course page on a phone outside in bright sunlight benefits from good contrast.
Instructional designers should check contrast rather than relying on visual judgment alone. Accessibility checking tools and contrast analyzers can help identify combinations that may cause problems.
Good visual design and accessibility are not competitors. A course can be attractive without asking learners to squint at it.
Mistake #5: Writing Unhelpful Link Text
Links labeled "click here," "read more," or simply displaying a long URL can create accessibility and usability problems.
Screen reader users may navigate through a list of links independently from the surrounding text. Imagine hearing:
"Click here."
"Click here."
"Read more."
"Click here."
Not terribly informative.
Descriptive link text tells learners where the link will take them.
Instead of:
"Click here to review the syllabus."
Use:
"Review the Course Syllabus."
Descriptive links improve navigation for assistive technology users and make course pages easier for everyone to scan.
Mistake #6: Posting Videos Without Accurate Captions
Video has become a standard part of online learning, but video content should be accessible to learners who cannot hear or fully process the audio.
Captions should communicate spoken dialogue and other meaningful audio information needed to understand the content. Automatically generated captions can provide a starting point, but they should be reviewed and corrected before students rely on them.
Errors in automated captions can range from mildly amusing to instructionally disastrous. Technical terminology, names, acronyms, and specialized vocabulary are especially vulnerable to transcription errors. One incorrectly captioned term can completely change the meaning of an explanation.
Transcripts can also provide learners with another way to access and review information. However, a transcript should not be treated as a substitute for synchronized captions when captions are needed for the video itself.
Accessible multimedia gives learners multiple ways to engage with course content while preserving the instructional meaning of the original material.
Mistake #7: Uploading Inaccessible Documents
A course page may be accessible while the files linked from it are not.
Word documents, PowerPoint presentations, spreadsheets, and PDFs all require accessibility considerations. Common problems include missing headings, poor reading order, inaccessible tables, missing alt text, insufficient contrast, and scanned PDFs that contain images of text rather than readable text.
PDFs deserve particular attention because instructors often assume that saving something as a PDF automatically makes it accessible. It does not.
Whenever possible, accessibility should begin in the original source document. Creating accessible Word or PowerPoint files before converting them is usually much easier than trying to repair accessibility problems later.
Instructional designers should also question whether every document needs to be a downloadable file at all. Sometimes information is more accessible, responsive, and easier to maintain when placed directly on an accessible course page.
Mistake #8: Creating Complicated Tables
Tables are useful when information genuinely requires rows and columns. They become problematic when they are used primarily to control page layout or when their structure becomes unnecessarily complicated.
Accessible data tables should have clearly identified headers and a logical structure that assistive technologies can interpret. Merged cells, nested tables, blank rows used for spacing, and unusually complex layouts can make relationships between data difficult to understand.
A good question to ask is whether the information truly needs to be presented as a table. If the content can be communicated more clearly using headings and lists, a table may not be the best choice.
When a table is appropriate, keep it as simple as the content allows.
Your learners came to the course to learn the subject matter, not to solve an escape room hidden inside a spreadsheet.
Mistake #9: Forgetting About Keyboard Navigation
Not everyone uses a mouse.
Some learners navigate digital environments using keyboards, switch devices, voice control, or other assistive technologies. Interactive activities should therefore be usable without requiring precise mouse movements.
Keyboard accessibility affects elements such as:
- Navigation menus
- Buttons
- Forms
- Interactive activities
- Quizzes
- Multimedia controls
- Third-party learning tools
This becomes especially important when selecting external educational technologies. A tool may look impressive during a demonstration while still creating serious barriers for learners who cannot operate it using a mouse.
Accessibility should therefore be part of technology evaluation, not something considered after the license has already been purchased and the activity has been built.
Mistake #10: Making Instructions Depend on Sight or Sound
Instructions sometimes unintentionally assume every learner interacts with content in the same way.
Examples include:
- "Click the green button on the right."
- "Look at the image below."
- "Listen for the tone before continuing."
These directions depend on sensory information that may not be available to every learner.
Instead, identify items by meaningful names or functions.
For example:
"Select the Submit Assignment button."
Specific language improves accessibility while also making instructions clearer for everyone.
Mistake #11: Assuming the Accessibility Checker Found Everything
Accessibility checkers are extremely useful tools. They can identify many common problems quickly and should absolutely be part of the review process.
They are not, however, substitutes for human judgment.
A checker may determine that an image contains alt text, but it cannot always determine whether that text meaningfully communicates the image's instructional purpose. It may identify that headings exist while failing to determine whether the resulting organization actually makes sense to learners.
Accessibility requires both automated testing and thoughtful review.
The green checkmark is reassuring.
It is not permission to stop thinking.
Mistake #12: Treating Accessibility as a Final-Step Checklist
Perhaps the most damaging accessibility mistake is waiting until the course is finished before thinking about accessibility.
Retrofitting an inaccessible course can require substantial time and effort. Designing accessibly from the beginning usually makes the process much more manageable.
Accessibility can be considered while:
- Selecting course materials
- Creating documents
- Recording videos
- Building assessments
- Choosing technologies
- Designing course pages
- Developing learning activities
This approach also aligns well with Universal Design for Learning because both encourage instructors and designers to anticipate learner variability rather than waiting for barriers to appear.
Accessible course design is not about predicting the needs of one particular student.
It is about reducing unnecessary barriers before learners encounter them.
Start Small, but Start Intentionally
Looking at a long list of accessibility considerations can feel overwhelming, especially when reviewing an existing course that has accumulated materials over several semesters.
You do not have to fix everything simultaneously.
Start with high-use and high-impact content. Review the syllabus, course orientation materials, frequently accessed documents, major assessments, instructional videos, and essential learning resources first. Then build accessibility review into the regular course maintenance process.
More importantly, change how new materials are created.
Fixing one inaccessible document helps one document.
Learning to create accessible documents changes everything that comes afterward.
Final Thoughts
Accessibility is not an extra feature added to an online course after the instructional design is complete. It is part of good instructional design.
Clear headings improve navigation. Descriptive links improve usability. Captions provide flexibility. Strong color contrast improves readability. Accessible documents make instructional materials available to more learners.
Most accessibility mistakes are not created because instructors intend to exclude anyone. They often happen because accessibility was never considered during the design process.
That gives instructional designers an important opportunity.
We can help move accessibility from something people fix later to something they simply know how to design from the beginning.
And that is a much better place for accessibility to live.
References
CAST. (2024). CAST Universal Design for Learning guidelines version 3.0. https://udlguidelines.cast.org/
U.S. General Services Administration. (n.d.). Authoring meaningful alternative text. Section508.gov. https://www.section508.gov/create/alternative-text/
U.S. General Services Administration. (n.d.). Making color usage accessible. Section508.gov. https://www.section508.gov/create/making-color-usage-accessible/
World Wide Web Consortium. (2024). Web Content Accessibility Guidelines (WCAG) 2.2. https://www.w3.org/TR/WCAG22/
World Wide Web Consortium. (n.d.). How to meet WCAG (quick reference). Web Accessibility Initiative. https://www.w3.org/WAI/WCAG22/quickref/