How to Make a PDF Accessible: Alt Text, Screen Readers, and the Rules You Need to Know

An accessible PDF is one a screen reader can actually read aloud in the right order, with images described in words instead of skipped in silence. Most PDFs published today fail that test — not out of neglect, but because the tools people use to create PDFs don't make accessibility the default. That gap has become a legal issue, not just a courtesy one: the European Accessibility Act became enforceable on June 28, 2025, and 2026 is the first full year national regulators are actively supervising against a deadline that has already passed. Here's what "accessible PDF" actually requires, and how to fix the single most common gap — missing alt text — yourself, for free.

Why this matters right now, not eventually

The EAA applies to a broad range of digital products and services offered to EU consumers, and it references WCAG 2.1 Level AA as its baseline accessibility standard through the European technical standard EN 301 549. Enforcement is handled at the member-state level, and penalties are not symbolic — reported fines run up to roughly €500,000 in Germany and up to 5% of annual revenue in Italy for non-compliance. Businesses with fewer than 10 employees and under €2 million in annual turnover are exempt from some EAA obligations, but everyone else distributing PDFs to EU consumers — invoices, reports, contracts, product documentation — is expected to meet the standard. In the US, Section 508 requires the same broad approach (built on WCAG) for federal agencies and their contractors, and a growing number of state-level laws follow a similar pattern.

What "accessible" actually means for a PDF

Accessibility standards are built around four principles, often abbreviated POUR: content has to be Perceivable (you can sense it, whether visually, audibly, or through touch), Operable (you can navigate it, including by keyboard alone), Understandable (the language and structure make sense), and Robust (it works reliably with assistive technology like screen readers). For a PDF specifically, this breaks down into a few concrete requirements:

• Tagged structure — headings, paragraphs, lists, and tables need to be marked as such internally, so a screen reader can announce "Heading 1: Annual Report" instead of reading everything as one undifferentiated block of text.
• Alt text on images — every meaningful image, chart, or diagram needs a text description of what it shows, so a screen reader user gets the same information a sighted reader gets by looking at it. A chart showing quarterly sales, for example, needs alt text describing the actual trend, not just "chart."
• Logical reading order — the order assistive technology reads content in has to match the order a sighted reader would visually follow, which isn't automatic in multi-column layouts.
• Real, extractable text — a scanned page that's really just a photo of text is invisible to a screen reader entirely, no matter how it looks to a human.
• Form field labels — fillable forms need labeled fields, so assistive technology can announce what each field is for.

The single most common gap: missing alt text

Of everything on that list, missing alt text on images is consistently the most frequent and highest-impact accessibility failure in real-world PDFs, because most document-creation tools simply don't prompt for it. Someone drops a screenshot, a chart, or a logo into a document, exports to PDF, and the image carries no description at all — a screen reader either announces it as "image" with no context, or skips it silently. For content-heavy documents like annual reports, product manuals, and government forms, this alone can make large sections of the document effectively unusable for a screen reader user.

Step-by-step: adding alt text to a PDF

1. Open Alt Text Tagger and load your PDF — nothing is uploaded, the file is read and edited entirely in your browser.
2. The tool detects the images embedded in your document and lets you step through them one at a time.
3. For each image, write a concise, specific description of what it shows or what function it serves — not "image of a chart" but "bar chart showing revenue growing from $2M to $5M between 2023 and 2026." For purely decorative images that carry no information (a background flourish, a divider line), mark them as decorative so screen readers skip them instead of announcing something meaningless.
4. Save the tagged file — the alt text is embedded directly into the PDF's structure, so it travels with the document wherever it's opened or shared.

Good alt text is short and specific. Describe what the image communicates, not that it's an image — "Photo of the product's side profile showing the USB-C port" is useful; "photo1.jpg" or "an image" is not.

If the PDF is scanned, alt text alone won't fix it

A scanned document — pages that are really just photographs of text — has no real text layer for a screen reader to read in the first place, and no amount of image alt text solves that. That's a different problem with a different fix: run the file through OCR PDF first to convert the scanned pages into real, selectable text. Once the document has an actual text layer, adding alt text to any remaining embedded images (photos, diagrams, stamps) with Alt Text Tagger completes the picture.

What this tool covers, and what it honestly doesn't

Alt Text Tagger solves the single most common and highest-impact accessibility gap: missing image descriptions. It does not perform full PDF/UA structural remediation — rebuilding heading hierarchy, table header associations, or reading order from scratch is a more involved job, often requiring specialized software or a manual accessibility audit, particularly for complex layouts like multi-column reports or data-heavy tables. If you're preparing a document for formal compliance certification, treat alt text as the highest-value first step, not the last one — it's the fix that closes the biggest gap for the least effort, but it isn't the entire standard by itself.

Who actually needs to do this

Beyond EU businesses covered by the EAA and US federal contractors under Section 508, this is simply good practice for anyone who publishes PDFs a broader public will read — universities, nonprofits, local government, and any business whose customers include screen reader users, which is a larger group than most people assume. If you're also thinking about mobile readability more broadly, pairing accessible PDFs with a reflow-friendly reading view — see Reflow View — covers the related but distinct problem of reading dense PDFs comfortably on a small screen.

A quick checklist before you publish a PDF publicly

• Does every meaningful image have a specific, descriptive alt text — not a filename, not left blank?
• Are purely decorative images marked as decorative so screen readers skip them?
• Is the document real, selectable text — not a scanned image of a page — or has it been through OCR?
• Do form fields (if any) have labels a screen reader can announce?
• Does the reading order match the visual order, especially in multi-column layouts?

If you can only do one thing on that list today, do the first one — alt text on images is the fix most documents are missing entirely, and it's the one you can complete in a single pass through Alt Text Tagger without any specialized software.

Common questions

Does every image need alt text? No — purely decorative images (dividers, background flourishes) should be marked decorative rather than given a description, since assistive technology should skip them rather than announce something meaningless. Every image that conveys information does need it.

Is a "tagged" PDF the same as an accessible PDF? Tagging is necessary but not sufficient. A PDF can be tagged and still fail accessibility if the tags are in the wrong order, images lack descriptions, or table headers aren't properly associated with their data. Tagging is the mechanism; accessibility is the outcome.

Do small businesses have to comply with the EAA? Microenterprises — fewer than 10 employees and under €2 million in annual turnover — are exempt from some EAA obligations, but the exemption is narrower than many assume and doesn't cover every requirement, so it's worth checking the specific exemptions rather than assuming blanket exclusion.

The short version

Accessible PDFs aren't a nice-to-have anymore in a growing number of jurisdictions, and even where they're not strictly required, missing alt text is an easy, high-impact fix. Start with the images in your most-viewed documents, describe what they actually show, and run scanned pages through OCR first so there's real text underneath the images to begin with.