PDFSlim
PDF Accessibility Checker

PDF Accessibility Checker
For audits before publishing or submission.

Check your PDF for WCAG 2.1 and Section 508 compliance - language tags, tagged structure, The audit runs in your browser, which helps when the document still contains internal material under review.

No UploadsBrowser OnlyLocal Processing

Drop PDF for Accessibility Audit

Supported: PDF

How PDF Accessibility Works

01

Drop Your PDF

Your file loads directly into browser memory. Nothing is uploaded to any server.

02

Real Structure Checks

We read the actual PDF catalog - language tags, MarkInfo, outlines, form field names, and metadata properties.

03

Review Results

Each check shows pass, warning, or fail with a plain-language explanation of what to fix.

04

Download PDF Report

Export a clean PDF audit report to share with clients, compliance teams, or keep on file.

WCAG 2.1 & Section 508 Explained

What is WCAG?

The Web Content Accessibility Guidelines set the global standard for accessible digital content. WCAG 2.1 Level AA is the most widely required compliance level.

Section 508

US federal law requiring that all government electronic content is accessible to people with disabilities. Applies to any organisation receiving federal funding.

Browser-Based Privacy

Accessibility Checker workflow notes

Accessible documents are easier to use for everyone, not only for people using assistive technology. Reviewing a PDF for accessibility means looking at heading structure, reading order, contrast, labels, and whether the file can be understood without guesswork.

Best use cases

  • Improve internal documents before sharing them with a broad audience.
  • Check reports, forms, and guides for common accessibility barriers.
  • Support more inclusive reading and navigation across devices and contexts.

Before you share

  • Use meaningful headings and logical section order.
  • Keep contrast and font sizing readable for ordinary viewing conditions.
  • Review forms and images so they still make sense without visual guesswork.

Practical limits

  • Accessibility Checker works on the file you provide, but it cannot correct source problems such as missing fonts, broken scans, or incomplete document structure on its own.
  • Performance depends on the memory and CPU available in the current browser tab, so very large files or image-heavy PDFs can still take longer to finish.
  • The browser-based workflow keeps files private and fast to process, but you should still inspect the final PDF before sending it to a client, portal, or records team.

Every tool runs in your browser, so there is no upload queue slowing the job down.

That is useful for private work and for large files on limited bandwidth.

Knowledge Hub

Master Document Security & Workflows

Read practical guides that explain when to use each tool, what to check before sharing a file, and how to avoid common document mistakes.

100% Offline Analysis
Actionable Technical Guides
AccessibilityMatching guide

What to Review When You Want a PDF to Be Easier for Everyone to Use

A practical accessibility guide focused on readable structure, better navigation, and fewer barriers for real readers.

Workflow tips
Common mistakes