- Source document
- Converting to PDF
- What are tags?
- Accessibility Check
- Document issues
- Amending tags
- Manually adding tags
- Checking your work
Important: PDF accessibility work requires Adobe Acrobat Pro. This is the licenced (paid for) version of the software. If you haven't got this, please do not convert your document to PDF.
PDF stands for Portable Document Format. Adobe created the PDF to solve the problem of sharing documents that were created in various file formats. The content creator may have used an application to create a document, which the user does not have installed on their machine. This meant that they couldn't open the document. The PDF allows everyone with a PDF reader to open the document. The problem is that PDFs are rarely accessible for everyone.
It is worth remembering that PDF accessibility is a contentious issue. There are those who adamently state that PDFs can never be made fully accessible and those who prefer them to some source documents for accessibility. The one fact that is certain, is that PDFs require a lot more work to be made accessible than the source documents. For this reason, we will start with the source document.
If you have access to the source document, this is by far the best place to start. It is much easier to fix accessibility issues in the source document than in a PDF. If the source document was created in Word or PowerPoint, you can refer to my resources on how to make these accessible.
Most applications provide options for making your source document accessible. The more accessibility work you can do here, the better. For every accessibility issue that remains in the source document, it is likely to be multiplied when converted to PDF.
Converting to PDF
It is important to follow the correct procedure for converting your document to PDF. This will ensure that accessibility features will be carried through to your PDF. This will make the next steps easier for you.
Please note: If you print to PDF from any application or web page, the resulting PDF will not be tagged and will require full manual tagging to make it accessible.
What are tags?
Web developers will already be familiar with tags, as they form the basis of HTML code. A tag tells the browser or screen reader what type of content something is. Most text is tagged as paragraphs with a
<p> tag. The main heading on a page is tagged with a
<h1> tag, followed by
<h2> tags, and so on.
In a PDF, tags perform a similar role, except that they don't affect the actual content on a page. On a webpage, if tagged content is missing, it will not display, whereas in a PDF it will, but screen readers will not be able to access it. Tags are therefore critical to PDF accessibility.
We will look at the different types of tag in a later section.
Adobe Acrobat Pro allows you to perform an automated accessibility check. As with any automated tool, it cannot find all errors and you still need to do many manual checks yourself, but it is nevertheless a useful tool.
When you perform an accessibility check in Adobe Acrobat Pro, the first section of results is about document issues. Common errors are missing document title and missing language. These must be fixed.
One of the issues that the accessibility checker always asks you to manually check is the reading order. The best place to do this is in the tags pane. If you started with an accessible source document and converted it correctly to PDF, this should be relatively easy.
Manually adding tags
This section almost merits its own website, it is so involved. Before you can manually add tags, you need to create a tags root. Then you can add all different types of tag and associate them with text that is visible on the page. As in the previous section, there should be no empty tags.
Please select from the following pages to view how-to videos for each type of tag.
- Create tags root
- Create section tags
- Heading tags
- Paragraph tags
- Figure tags and artifacts
- List tags
- Link tags
- Table tags
I wrote a blog post on how to create forms in a PDF. It's one of the things I never do, because PDFs are strongly discouraged in my workplace. I learned it specially for an exam but was really quite excited about how well it all worked.
Checking your work
There are several steps that I recommend to check your work before declaring it finished.
- In the reading order pane, check that you have no rogue objects. Things like empty lines can be marked as artifacts.
- Rerun the accessibility check in Adobe Acrobat Pro.
- Use a screen reader to check that it works correctly.