What are the WCAG?
The WCAG (Web Content Accessibility Guidelines) are the internationally authoritative guidelines for digital accessibility. They are published by the World Wide Web Consortium (W3C); the current version is WCAG 2.2 (W3C recommendation since October 2023). The guidelines describe how digital content must be designed so that people with disabilities can use it - for example with screen readers, magnification software or keyboard-only operation.
The WCAG is based on four principles:
- Perceptible: Content must be accessible to all senses - for example through text alternatives to images and sufficient contrast.
- Operable: Navigation and interaction must work without a mouse; Users must be able to orient themselves in the document.
- Understandable: Content and operation must be comprehensible - this also includes ensuring that the language of the content is technically declared.
- Robust: Content must be able to be reliably interpreted by assistive technologies - this requires a clean technical structure.
Each principle is clarified by concrete success criteria, which are assigned to one of three compliance levels:
| Level | Meaning |
|---|---|
| A | Minimum requirements – without them, content is not accessible to many users. |
| AA | The legal standard common in the EU, including EN 301 549 and BITV 2.0. |
| AAA | Extended requirements that are generally not fully required by law. |
In practice, “WCAG compliant” almost always means: conformity level AA, i.e. all criteria of levels A and AA.
Do the WCAG also apply to PDF documents?
Yes. The WCAG are formulated in a technology-neutral manner and relate to content – not just websites. The European standard EN 301 549 creates a formal bridge to documents: Chapter 10 (“Non-web documents”) transfers the WCAG success criteria of levels A and AA to documents outside the web, including PDFs.
This becomes relevant wherever laws refer to EN 301 549:
- The German Accessibility Strengthening Act (BFSG) and the European Accessibility Act (EAA) require accessible digital offers for certain products and services - PDFs such as contract documents, product information or invoices are part of these offers. Our article explains which providers are affected BFSG and accessible PDFs.
- For Authorities, universities and the public sector BITV 2.0 (§ 3) also refers to EN 301 549 - the requirements have been in effect there for years, expressly also for file formats such as PDF.
A PDF that is made available on a website or in a customer portal must therefore meet the relevant WCAG criteria just as much as the website itself. Note: EN 301 549 in the currently harmonized version references WCAG 2.1; WCAG 2.2 is the current W3C recommendation and the sensible benchmark for new documents.
The most important WCAG criteria for PDFs at a glance
Not every WCAG criterion is relevant to documents - many concern interactive web functions. These success criteria are particularly crucial for typical PDFs:
| Criterion | Level | Request in PDF |
|---|---|---|
| 1.1.1 Non-Text Content | A | Images, graphics and diagrams need alternative text that describes the content. Purely decorative elements are marked as artifacts so that screen readers will skip them. |
| 1.3.1 Info and relationships | A | Headings, paragraphs, lists and tables must be marked as structure tags. Only then can a screen reader recognize what is a heading and what is a table header. |
| 1.3.2 Significant order | A | The reading order in the tag tree must follow the logic of the content - a common mistake, especially with multi-column layouts, info boxes and marginal columns. |
| 1.4.3 Contrast (minimum) | AA | Text needs a contrast ratio of at least 4.5:1 to the background (3:1 for large text). |
| 2.4.2 Page with title | A | The document needs a meaningful title in the metadata, which programs display instead of the file name. |
| 2.4.5 Different methods (correspondingly) | AA | Long documents need navigation aids - in PDFs, especially bookmarks that show the structure. |
| 3.1.1 Language of the site | A | The main language of the document must be technically stored so that the speech output selects the correct pronunciation. |
| 3.1.2 Language of parts | AA | Foreign language passages must be marked as such - for example English quotations in a German document. |
In addition, the basic requirement is that the text must be available as a real text and be readable by machine. A scanned document that only consists of page images fails criterion 1.1.1 - for a screen reader it is empty.
WCAG compliant PDF or PDF/UA compliant PDF – what’s the difference?
In short: The WCAG describes, What must be accessible – PDF/UA describes, How which can be implemented technically correctly in PDF format.
- The WCAG are technology neutral. For example, they require “Info and relationships must be programmatically determinable,” but do not specify which PDF tags should be used for this.
- PDF/UA (ISO 14289, currently PDF/UA-2) is the special standard for accessible PDFs. It precisely defines how tag structure, artifacts, metadata and embedded fonts must be designed. Criteria that are not a question of format - such as color contrast - are not regulated by PDF/UA.
Both standards complement each other: A document that is clearly structured according to PDF/UA meets the structure-related WCAG criteria; For full WCAG conformity, design requirements such as contrast are added. In practice, it is therefore advisable to consider both standards together. Our article explains what PDF/UA-2 requires in detail Understanding PDF/UA.
Typical WCAG errors in PDFs from practice
Many PDFs in circulation fail to meet the WCAG criteria, not out of bad faith, but because the tools do not provide any structure in the creation process. Most often we encounter:
- Scanned PDFs without a text layer: The document consists only of images of the pages. Screen readers cannot find text, search and copying do not work (violation of 1.1.1, among other things).
- Missing or incorrect tags from layout and office programs: Many export methods create untagged PDFs or mark everything as continuous text - headings, lists and tables are then not recognizable as such (violation of 1.3.1).
- Tables as pictures: Tariff or price tables are integrated as graphics. The data is visually present but inaccessible to assistive technologies (violation of 1.1.1 and 1.3.1).
- Incorrect reading order: In multi-column layouts, the reading order jumps back and forth between columns and boxes (violation of 1.3.2).
- Missing document title and missing language: Two small metadata with a big impact - without them, the speech output reads German texts with English emphasis and displays cryptic file names (violation of 2.4.2 and 3.1.1).
Especially in organizations with large document collections – for example Insurance, Banks or Authorities – these errors add up across thousands of existing documents.
How Accessful automatically corrects the machine-verifiable criteria
Accessful addresses exactly the structural level at which most WCAG violations occur in PDFs: The AI analyzes text, layout and image content, adds structure tags, corrects the reading order, creates alt text for images and graphics and sets document titles and document language - in over 110 languages and with results typically in seconds. The layout and content of your document remain unchanged; Only the structural level is changed. For each document you will receive an audit-ready report with which you can prove the implementation to testing bodies and audits.
This requires an honest distinction: Not every WCAG criterion can be corrected later in the file. The color contrast (1.4.3), for example, is a design decision in the source document - a tool that leaves the layout and design untouched cannot and should not change it on its own. Accessful shows such points in the test results so that you can specifically correct them in your templates. Questions about content such as understandable language also remain an editorial task.
The page shows how the automatic check and correction works in detail - via web app, API or on-premises PDF accessibility with AI. If you would like to know where your documents are today: Below scan.accessful.de check PDFs for free.