When organizations think about digital accessibility, websites are often the first thing that comes to mind. However, accessibility extends far beyond a website’s design and functionality. Every day, organizations create, publish, and distribute digital content, including PDFs, forms, reports, policies, spreadsheets, presentations, and other documents. If these materials are not properly structured for accessibility, they can create significant barriers for individuals with disabilities, even when the website hosting them is fully accessible.
This is where Section 508 of the Rehabilitation Act plays an important role. For organizations subject to its requirements, accessibility extends beyond simply making information available online. Digital documents must also be structured and formatted so individuals using assistive technologies can effectively access, navigate, and understand their content.
In this guide, we’ll explain Section 508 requirements in straightforward terms, explore best practices for creating accessible digital documents, and outline practical steps for evaluating and remediating existing content. The goal is to help organizations move beyond basic accessibility considerations and ensure their digital information is usable by everyone.
What is Section 508, and does it apply to PDFs?
Section 508 of the Rehabilitation Act establishes accessibility requirements for information and communication technology (ICT) developed, procured, maintained, or used by federal agencies. Its purpose is to ensure that individuals with disabilities, including federal employees and members of the public, have access to digital information and services comparable to that available to individuals without disabilities.
These requirements extend beyond websites and software to include electronic documents such as PDFs, forms, reports, and other digital materials. For organizations subject to Section 508, simply making a document available online is not enough. The content must also be accessible to individuals who rely on assistive technologies, such as screen readers, to navigate, understand, and interact with the information.
To keep up with our fast-moving digital world, the U.S. government updated its Section 508 rules back in 2017. When they did, they adopted WCAG 2.0 as the baseline rules for digital accessibility.
But technology has grown, and so have the guidelines. Recently, the U.S. Department of Justice updated its rules for state and local governments, requiring them to meet the newer, higher WCAG 2.1 standards for their websites, apps, and digital documents. At the same time, many organizations are already shifting to the even newer WCAG 2.2 rules.
Because of these changes, aiming for WCAG 2.1 or WCAG 2.2 today is the smartest path. It makes your compliance efforts much clearer, protects your work for the future, and matches where the entire industry is heading.
So does this law apply to the everyday PDFs we share? Yes, absolutely. A PDF is an electronic document, so it falls directly under Section 508 PDF compliance requirements. It does not matter whether a PDF is published on a public website or shared internally as official business. If someone using a screen reader or other assistive technology cannot read the information inside, the digital door stays closed.
What makes a PDF accessible?
In simple terms, PDF accessibility compliance means the file is built so that everyone can read and use it easily. When a document is accessible, a person using a screen reader or keyboard navigation can do everything a sighted reader can do. They can read the content, understand the overall structure, and move from one section to another. They can also hear descriptions of images, use working links, fill out interactive forms, and make sense of tables.
But here is an important trap to avoid: making a PDF searchable is not the same as making it accessible. While having searchable text is a great first step, it does not mean a screen reader can actually understand how the document is organized.
Key requirements for PDF accessibility compliance (Section 508)
To make sure your PDFs are welcoming and accessible to everyone, you need to design them with a few key guidelines in mind. Here is a breakdown of the eight essential requirements for Section 508 compliance.
1. Proper tags and document structure
Think of PDF tags as a hidden blueprint. Without tags, a screen reader just sees a large block of flat text with no organization. Tags act like labels behind the scenes, showing assistive technology exactly what a heading, a paragraph, a list, a table, an image, or a link is. These tags give the document its structural meaning, so users can navigate and understand what they are reading.
2. Correct reading order
A page can look great visually and still confuse a screen reader. For example, if a document has two visual columns, a sighted person naturally reads down the first column and then starts the second. But a screen reader might get confused by the layout, reading straight across from the bottom of the first column to the top of the next. Keeping a logical reading order makes sure the content makes sense to everyone.
3. Alternative text for images
If a picture is worth a thousand words, we need to make sure those words are spoken to everyone. Photos and charts that carry meaning must have clear, descriptive alternative text (alt text) so screen readers can describe them.
When writing these descriptions, keep them concise and avoid starting with phrases like “image of,” since screen readers already announce that the element is a graphic. Sighted authors should also set the image layout to “Inline with Text” to keep it wrapped directly inside the logical reading flow.
But when it comes to decorative graphics (such as background shapes or accent lines) that do not carry any meaning, the rules change. In web development, you can hide a decorative image by simply leaving its alt text blank (using alt=””). Doing this in a PDF, however, is a major mistake that will fail strict PDF/UA validation. In a PDF, you cannot leave a structural Figure tag in the tag tree with empty alt text. Instead, the graphic must be explicitly marked as an “Artifact”. This completely removes the image from the document’s navigation structure, allowing screen readers to skip over it cleanly.
Finally, keep in mind that while automated accessibility tools can easily tell you if alt text exists, they cannot tell you if the description actually makes sense or explains the chart correctly. This is why manual human review is so critical.
4. Accessible tables
Data tables are great for organizing complex facts, but they can be a nightmare for screen readers if they are not set up properly. An accessible table needs clearly defined header rows and columns that connect logically to the data cells beneath them. That way, when a screen reader navigates a specific number, it can announce exactly which category that number belongs to. Also, we should never use tables just to make a page look pretty or for visual layout.
5. Accessible links and navigation
Every link in your document needs to be a clear signpost. Sighted and non-sighted users alike should be able to identify a link immediately. The text of the link itself should be meaningful and tell the reader exactly where they are going, rather than saying “click here” or showing a raw web address. Additionally, links must work flawlessly with keyboard-only navigation so everyone can select and open them.
6. Color, contrast and visual presentation
To make your document easy on the eyes, you must use high color contrast between your text and the background. This is incredibly helpful for people with low vision or color blindness. Just as importantly, you should never rely on color alone to explain things. For example, if you say “the red items are late,” someone who cannot see red will be left in the dark. Instead, use a text label or a distinct symbol alongside the color to be clear.
7. Accessible forms and interactive elements
If your PDF includes interactive forms, each fillable box must have a clear label so the user knows exactly what to type. The document must also follow a logical tab order, meaning when a user presses the Tab key, they move naturally from one field to the next in the correct sequence. Forms should also provide clear instructions, explain errors if something goes wrong, and be completely operable with just a keyboard.
8. Document properties and language
Finally, every document needs basic identity settings. You must set a clear, descriptive document title in the file properties. This is crucial because screen readers announce this title first when the file opens, rather than reading a confusing file name like “draft_v2_final”. You also need to set the official reading language in the document settings so screen readers use the correct pronunciation rules.
What about scanned PDFs?
Is a scanned PDF accessible? Usually, not by default.
There is a big difference here. A scanned PDF is essentially a flat photo of a page. Because it is an image, screen readers and other assistive technologies cannot read, search, or reflow the words on it.
An accessible PDF, by contrast, contains real, structured text that assistive tools can interpret, navigate, and present in different ways (e.g., enlarged, reflowed, or read aloud).
To bridge this gap, we use Optical Character Recognition (OCR). OCR analyzes the image and creates a text layer so the words become selectable and searchable. However, OCR alone does not make a PDF fully accessible. It provides the raw characters, but it does not add:
- Semantic tags (headings, paragraphs, lists, tables, etc.)
- Correct reading order, especially in multi‑column layouts
- Alternative text for meaningful images and figures
- Proper handling of decorative graphics and scan noise as artifacts
Without this structure, a screen reader may present the entire page as one long, unstructured block of text with no landmarks or navigation points.
WCAG, Section 508 and PDF/UA: What’s the Difference?
When you dive into digital accessibility, you will quickly run into a lot of alphabet soup, specifically Section 508, WCAG, and PDF/UA. While they all work together to make the digital world more inclusive, they are actually very different.
| Framework | What It Is | Its Role |
|---|---|---|
| Section 508 | US federal law | Requires agencies to make digital content and data accessible |
| WCAG 2.0/2.1/2.2 (Level AA) | Global accessibility guidelines | Defines what “accessible” actually means, in measurable terms |
| PDF/UA (PDF/UA-1 and the newer PDF/UA-2, ISO 14289-2:2024) | Technical standard for PDFs | Specifies exactly how an accessible PDF file needs to be built |
Each has a distinct role in keeping your files both legally compliant and technically sound.
How to test a PDF for Section 508 compliance (PDF accessibility testing steps)
Testing a PDF is a lot like checking a building for safety. You cannot just look at the front door and assume the entire space is welcoming. Real PDF accessibility testing blends software checks with human judgment.
Step 1: Automated testing. Run the file through software checkers first. These tools are great at instantly catching technical, machine-detectable mistakes: missing tags, missing metadata, basic structural errors, and broken link setups.
The Matterhorn Protocol, the de facto global standard for PDF/UA accessibility testing, defines 31 checkpoints and 136 failure conditions. Of these, roughly 87 failure conditions can be evaluated automatically by software, while about 47 require human judgment, and 2 have no specific test. This means tools can verify much of the underlying structure, but a human reviewer is still needed to assess semantics, reading order, and the appropriateness of alternative text and other content.
Step 2: Manual review. Technology has limits. While an automated tool can verify that an image has alternative text, it cannot tell you if that text actually describes the picture. That is why manual human review is so critical. A real person needs to check if the reading order flows logically, if headings are used correctly, and if tables communicate data relationships properly.
Step 3: Assistive technology testing. The final step is experiencing the document just like a user would. This means navigating the file using only a keyboard, testing the zoom and reflow experience, and listening to the content through a screen reader.
By putting every document through a complete cycle (Automated check, Manual review, Assistive technology validation, Remediation, and Retesting), you ensure your files are truly compliant and welcoming to all.
How organizations can build an accessible document workflow
Instead of treating accessibility as an afterthought, where you write a document, publish it, find out it is broken, and scramble to fix it, it works far better to build it in from the start.
A proactive workflow keeps Section 508 compliance for documents part of the process from day one: start with an accessible source document, export it to an accessible PDF, run automated testing paired with manual validation, publish, and then keep monitoring for updates.
To make this work, organizations should provide author training so creators can use accessible templates natively. By establishing accessibility checks before publication, clear remediation workflows, and testing updated documents again, you turn compliance into a natural, stress-free habit.
Conclusion
Ultimately, digital accessibility does not stop at your website. Every PDF, form, and report your organization shares is a vital part of the user’s digital experience.
To build a truly inclusive strategy, we must use all the tools at our disposal. Section 508 gives us the legal rules, WCAG provides the global guidelines, and PDF/UA offers the technical map for the PDF format itself. For testing, automated tools quickly spot technical bugs, while manual and assistive technology testing confirm that real people can actually navigate and understand your content.
Making your documents accessible is a journey, and you do not have to walk it alone. The most successful teams combine quick software scans with real human reviews to find and fix issues. If you are ready to make your files truly welcoming to everyone, Tranistics is here to support you. We can help you spot hidden barriers in your PDFs and map out a clear, stress-free path toward accessibility.
Frequently Asked Questions
1. Does Section 508 apply to PDFs or just websites?
Yes. A PDF counts as an electronic document under Section 508, whether it is posted on a public website or shared internally. If assistive technology cannot read it, it does not meet the standard, no matter how the file is distributed.
2. Is a searchable PDF automatically accessible?
No. Searchable text just means the words can be found and copied. It says nothing about whether the document has proper tags, a logical reading order, or alt text, which is what a screen reader actually needs to make sense of the file.
3. Can I make a scanned document accessible with OCR alone?
No. OCR converts the scanned image into recognizable text, which is a necessary first step, but the document still needs semantic tags, a logical reading order, correct alt text for meaningful images, and proper handling of decorative elements before it meets accessible PDF requirements.
4. What tools do I need to test PDF accessibility?
A combination of three: an automated checker to catch technical errors, a manual review by a trained person, and a real screen reader or keyboard-only test. The Matterhorn Protocol defines 31 checkpoints and 136 failure conditions; of these, roughly 87 can be evaluated automatically by software, about 47 require human judgment, and 2 have no specific test. This means tools can verify much of the underlying structure, but a human reviewer is still needed to assess semantics, reading order, and the appropriateness of alternative text and other content.
5. How can Tranistics help improve PDF accessibility at my organization?
Tranistics can review your PDFs against Section 508, WCAG, and PDF/UA requirements, flag the hidden barriers, and map out a clear remediation plan so your documents are genuinely accessible, not just searchable.
