Accessibility Challenges with Embedded PDFs in HTML Viewers

When PDFs are embedded in web pages using PDF viewers that convert them to HTML, they often introduce significant accessibility challenges. Here are some real accessibility issues associated with this practice:

1. Loss of Proper Heading Structure

PDFs are typically structured with headings and other semantic elements that help screen readers and keyboard users navigate the document. When the PDF is converted to HTML, the heading structure can break down, resulting in a poorly organized document without proper headings or logical order.

2. Inaccessible Text and Images

Text and images within a PDF may lose their accessibility attributes, such as alternative text for images or proper tagging for text, during the conversion process. This means that images might not have meaningful descriptions, and text could become unreadable or unstructured.

3. Complex Layouts and Tables

PDFs often contain complex layouts, including tables, columns, and forms. These elements can be difficult to properly convert to HTML without losing the logical reading order or the functionality of interactive elements like form fields.

4. Inconsistent Text Flow and Reading Order

Many PDF viewers struggle to maintain the correct reading order when converting PDFs to HTML. Complex designs, such as multi-column layouts or sidebars, can result in text being presented in a confusing order, making it difficult for users to read the content in a logical way.

5. Missing or Incomplete Accessibility Metadata

PDFs can include accessibility features like metadata, document language, and tagging that are important for assistive technology users. When converted to HTML, this metadata is often lost or improperly handled, resulting in missing language settings or an absence of crucial navigation aids.

6. Keyboard Navigation Issues

Proper keyboard navigation is essential for users who cannot use a mouse. Embedded PDFs often do not translate well into accessible HTML structures, causing tab order to be disrupted or non-functional links and buttons.

7. Missing or Incomplete Annotations

PDFs often contain annotations, comments, or highlights that are critical for understanding certain content. When converting PDFs to HTML, these annotations might be lost or not properly presented.

8. Non-Responsive or Fixed Layouts

Many embedded PDF viewers present documents in a fixed layout that doesn't respond to different screen sizes or zoom levels. This makes it difficult for users on mobile devices or those who need to zoom in (e.g., low-vision users) to interact with the content.

Conclusion

Converting PDFs into HTML via embedded PDF viewers can result in various accessibility issues, including broken document structure, inaccessible text and images, poor keyboard navigation, and the loss of interactive elements. These issues make it difficult for users with disabilities to interact with the content, limiting their ability to fully engage with the document.