Accessibility guide

Accessibility is central to creating meaningful and inclusive learning experiences. As an Embed partner, you play an essential role in how accessibility principles are put into practice—both in the way you implement Coassemble’s course creation tools within your platform and in how you guide your customers to use them.

Overview

Coassemble has been independently verified as conforming to WCAG 2.2 Level AA standards.

Accessibility is a shared responsibility. Coassemble provides an accessible foundation for the learner experience, but accessible outcomes also depend on partner implementation decisions and course creators following best practices.

Shared responsibility: Coassemble, you, and your users

• Coassemble: Provides the underlying course creation tools, designed with WCAG principles in mind.
• You (Embed partner): Your implementation decisions (e.g. navigation, shell UI, theme overrides) directly impact accessibility outcomes.
• Your users (course creators): They must apply accessibility best practices when building courses (e.g. adding alt text, maintaining contrast, choosing screen types carefully).

Key accessibility practices for course creators

1) Add alternative text (alt text) for images

Images can bring content to life, but for learners who use screen readers those visuals need to be described in text form. Alt text provides a written description of an image so learners who cannot see it can still understand its purpose and meaning. Without alt text, a screen reader may skip the image or read out the file name, creating a poor learning experience.

Best practices:

• Be clear and concise: Keep alt text under 125 characters so it can be quickly read by screen readers.
• Describe the purpose, not just the appearance: Instead of saying “a chart,” write “bar chart showing sales growth over three years.”
• Avoid unnecessary phrases: Don’t start with “image of” or “picture of”—screen readers already announce that it’s an image.
• Include essential text: If the image contains text that isn’t repeated elsewhere, include it in the alt text.
• Leave decorative images blank: Don’t add alt text for purely decorative images so screen readers can skip them.
• Test for context: Ask yourself, “If this image were removed, would learners still get the same information?” If not, the missing context belongs in the alt text.

2) Ensure high contrast for text and UI

Color and contrast play a critical role in making digital content readable for everyone. Learners with low vision or color blindness may struggle to read text if it doesn’t stand out clearly against its background. Even well-designed content can become inaccessible if contrast isn’t considered.

Best practices:

• Start with defaults: Coassemble themes are built with sufficient contrast, so encourage customers to use presets wherever possible.
• Check custom colors: If they override default theme colors, they must manually check the contrast between text and background to ensure it follows WCAG guidance.
• Use reliable tools: Free resources like WebAIM’s Contrast Checker help confirm compliance quickly.

3) Choose accessible screen types

Different screen types can create different learning experiences—but they don’t all interact with assistive technologies in the same way. Choosing the right screen type helps ensure content remains accessible to all learners.

Guidance:

• Standard screens: All standard Coassemble screen types are compatible with screen readers, so they can be used confidently.
• Hotspot screens (use caution): Hotspots place interactive labels on images, which may not always be interpreted clearly by screen readers. If critical information is contained in a hotspot, ensure it’s also provided in text elsewhere.
• Embed screens (third-party content): The Embed screen allows third-party content (e.g. videos, interactive tools) to be included. Since accessibility varies widely across third-party providers, customers must check each tool for compatibility with screen readers and other assistive technologies before embedding.
• Provide alternatives: If a particular screen type or embedded tool cannot be made accessible, offer the same information in an alternative format (e.g. a text summary or downloadable file).

4) Ensure video content has captions

Video content is a powerful way to engage learners, but it also needs to be accessible. Learners may rely on captions to access video-based learning.

How to support captioning:

• When embedding videos from platforms like YouTube or Vimeo, use their built-in captioning tools.
• Upload caption files for the highest accuracy, or use auto-generated captions (always review and correct errors).
• Always enable captions for any instructional video.
• Keep captions synchronized with the video, and make sure they convey spoken content accurately, including important sounds (e.g. “[applause]” or “[music]”).
• Consider providing transcripts for video and audio content.

Important note:

• Coassemble does not generate or manage captions for videos uploaded directly to the platform. If users want to rely on YouTube/Vimeo captioning, they must caption videos in the source platform before embedding them in a course.

5) Avoid placing text inside images

It’s important that text is provided in a format assistive technologies can read. Any text embedded inside an image (for example, screenshots of slides, infographics, or banners with text) typically won’t be detectable by screen readers.

Best practices:

• Avoid uploading images that contain large blocks of text.
• Place text directly in the course content where assistive technology can read it.
• If using an image with essential text (e.g. a chart or labeled diagram), provide that text in the alt text or as a supporting description alongside the image.

How Embed partners can support customers

• Educate customers on accessibility best practices.
• Highlight how implementation decisions (UI, color schemes, navigation) impact accessibility.
• Provide resources such as WCAG guidance and accessibility testing tools.
• Encourage testing with assistive technologies before course launch.

Summary

Coassemble’s tools are designed with WCAG principles in mind and have been independently verified for WCAG 2.2 Level AA conformance. Accessible outcomes depend on shared responsibility across Coassemble, Embed partners, and course creators. By following the practices above—alt text, contrast, accessible screen choices, captions, and avoiding text-in-images—you can help deliver inclusive learning experiences for all learners.