Accessibility of PDF documents means that digital documents must be structured in such a way that people with visual impairments or other limitations can use them in full. Specifically, PDFs need clear headings, alternative text for images and correctly labeled tables so that screen readers can read out the content clearly. The legal basis for this is the Accessibility Reinforcement Act, which will also oblige private companies from 2025.
Key Takeaways
- PDF documents in the private sector must be accessible from 2025, although the Accessibility Reinforcement Act is less strict than the requirements in the public sector: the more accessibility, the better.
- Accessibility in PDFs concerns structure, headings, alternative texts for images and correctly labeled tables so that screen readers can read out the content in a way that blind people can understand.
- The subsequent transformation of endurance testing documents is technically possible, but takes about half a second per document, so that 100 million documents still take five to six days even with 100 parallel instances.
- Affected people with disabilities must be included in tests because sighted testers are systematically biased when evaluating document structure and screen reader usage.
Why PDFs must also be accessible
Accessibility is not limited to websites. Contracts, invoices and policies that are sent as PDFs are also included. They are part of digital services and must be accessible to people with disabilities.
This has long been mandatory in the public sector. With the Barrier-Free Accessibility Reinforcement Act, it is now the turn of the private sector, where documents play a major role. In the financial sector in particular, contracts, invoices and policies are constantly sent back and forth, often as PDFs.
One difference to the public sector is worth noting. The Strengthening Act does not make the same comprehensive demands as the regulation for local authorities. The motto here is rather: the more accessibility, the better. According to Baris Güldali, sanctions are also applied with a sense of proportion and according to the severity of the offense.
What accessibility for PDFs means in concrete terms
Accessibility means access for everyone, including those with visual impairments, hearing impairments or limited receptivity. With PDFs, the first potential barrier begins when the document is opened, for example when using the mouse or keyboard.
Anyone reading without a disability immediately thinks about what is visible. You start at the top left and end up at the bottom right with the invoice amount. Blind people often do not have this spatial perception. For a screen reader to be able to read the document correctly, it needs a clear structure.
The requirements are already known from the HTML area:
- recognizable headings and their linking to the appropriate sections
- Alternative texts for images so that a screen reader can convey the image content
- Tables with table headings so that it is clear which value is under which column
Tables are a typical problem area. They are used to structure data, but are often unconsciously used purely for formatting, to move text to the left or right. This is precisely where accessibility hurdles arise.
Baris focuses on readability. Input options in forms, audio and video content in PDFs are also affected, but are not included here.
Which tools help with the check
There is a wide range of tools for checking PDF documents. Associations and specialized institutions list software and hardware tools. This knowledge is widespread in the usability community, for example around eye-tracking.
With HTML, a URL is often enough to get a report back. For PDFs, there are both readers and testing tools. Standard screen readers on smartphones and mobile devices read out a PDF, provided it is well structured. There is also specialized software that can be installed and started without much effort.
However, these tools only work if the level of information in the document allows it. A checking tool such as PAC evaluates PDF/UA and WCAG criteria and shows where the problem lies. If the PDF was created from a Word document or Adobe technology, it is usually easy to see how a defect can be rectified.
Making existing documents accessible is a migration project
The transformation of old PDFs into accessible form is not a push of a button, but a separate project involving design, implementation and testing. This was demonstrated by a proof of concept that Baris supported in output management for a major bank.
Even the concept is challenging. What accessibility means for a specific document, which content, tables and images are defined or provided with alternative texts, can only be clarified together with the specialist department.
The implementation was carried out programmatically with Java libraries. PDFs can be edited with such tools, which works. The more chaotic the incoming documents, the more you have to transform. In this case, the documents had been optimized for years to look pixel-perfect for the output. Now they had to be brought into a well-formed structure, content tagged, logos, tables and images provided with semantics, fonts and contrasts re-evaluated.
Guys, this is a migration project. Like a major bank merger: data migration is a science in itself, and document transformation is also a science in itself.
Baris Güldali
Why performance becomes a bottleneck with large volumes
With millions of documents, processing speed determines feasibility. Most of the documents in the example were 7 to 10 pages long and took around half a second to transform.
That sounds fast, but it adds up. The following calculation makes the effect visible.
| Scenario | Effort |
|---|---|
| 100 million documents, 1 instance, ~0.5 sec | over 500 days |
| 100 million documents, 100 instances | 5 to 6 days |
| pure text transformation | 300 to 800 milliseconds |
| transformation with images | over one second |
Banks process hundreds of millions of digital documents every year. Without parallelism and multiple cloud instances, a transformation on this scale is impossible. Even then, a big bang run remains a multi-day project that needs to be well prepared.
Not every existing document needs to be touched
The obligation applies to future documents, not necessarily the entire archive. Future documents must be accessible, as must new versions, such as a new policy or contract form.
What is already in the archive and has only served its retention period, for example over ten years, does not need to be touched. Transformation only comes into play when an existing document is made available again as part of a digital product.
An exception is also possible if it can be justified. In the case of exotic or audio content that cannot be sensibly converted, the costs and benefits must be weighed up. According to Baris, the legislator is more relaxed here than in the municipal sector.
Those affected belong in the test
Those who see for themselves are biased. Sighted people expect a certain place for the salutation, a certain place for the address, and also interpret the results of the tools according to this expectation. A blind person deals with the technology in a completely different way, right from the start.
This realization came a little late in the project. Baris is now working with a local association in Paderborn to gather feedback from blind people of varying degrees of blindness. This is already underway in the HTML area and is to be followed up at PDF level.
When you implement accessibility, involve people with disabilities. You build the product for them and their feedback reveals gaps that you cannot see yourself.
Complying with regulations is not enough, a welcoming culture is the goal
Accessibility pays off beyond the obligation because it improves product quality for everyone. Good structure, comprehensibility and automatic processability are quality features that also benefit people without disabilities.
Baris draws a comparison with a cruise ship that was highly specialized in this area. There, not only were laws implemented, but a welcoming culture was created and guests with disabilities felt at ease.
The real question therefore goes beyond regulation. How do you build software that disabled people enjoy using? If you evaluate the effort in this direction, you can see accessibility as an advantage to make digital products and services better.
