An online accessibility check is a useful first screen, not a compliance certificate. PDFCheck looks for five basic signals: tagged structure, a document title, a declared language, extractable text, and bookmarks.
Those signals can reveal obvious gaps. They cannot tell you whether the reading order makes sense, alternative text is useful, tables are correctly tagged, forms have labels, or a screen-reader user can complete the document.
What the Five Signals Mean
| Signal | Why it helps | What it does not prove |
|---|---|---|
| Tagged PDF | A structure tree is present | Correct tags or reading order |
| Title | The document can have a meaningful name | That readers display it correctly |
| Language | Assistive technology can choose pronunciation rules | Correct language changes within the file |
| Extractable text | The file is not only page images | Accurate text or sensible reading order |
| Bookmarks | Long documents may offer faster navigation | A complete heading structure |
What WCAG and PDF/UA Add
WCAG defines testable accessibility success criteria for web content, including PDF documents delivered on the web. The W3C publishes PDF techniques for areas such as tagged text, headings, reading order, alternative text, forms, tables, bookmarks, and OCR. The techniques are informative; conformance is determined against the success criteria.
PDF/UA is the ISO standard family for accessible PDF. It gives PDF-specific requirements for a predictable structure that assistive technology can use. A file can show all five PDFCheck signals and still fail WCAG or PDF/UA. The PDF standards guide explains where PDF/UA fits alongside PDF/A, PDF/X, and signature profiles.
A Complete Review Workflow
1. Start with the source document
Use real headings, lists, table headers, descriptive links, document language, and meaningful alternative text before export. See the accessible Word-to-PDF guide.
2. Run the five-signal screen
Open the PDF Accessibility Checker. Treat a missing signal as a clear repair item, and a passing signal as a reason to continue—not to stop.
3. Use a standards-aware validator
Check the required WCAG level and PDF/UA profile with a tool approved by your organization.
4. Inspect the tag tree and reading order
Verify headings, paragraphs, lists, tables, figures, artifacts, form labels, and language changes.
5. Test real tasks
Navigate by heading and link, read complex pages with a screen reader, complete forms using the keyboard, zoom text, and check visual contrast.
6. Fix the source and retest
When possible, repair the authoring file and export again. PDF-only remediation is often harder to maintain.
Sources
Bottom line: use the online check for triage. Accessibility approval needs deeper automated checks, manual inspection, and task testing with assistive technology.