Preflights a PDF for accessibility in the browser: tagging and structure element types, document and page language, a title shown in the window, alternate text on figures, extractable text (scans are flagged for OCR), Unicode mapping, heading nesting, tab order and form field descriptions. Each finding cites the PDF/UA-1 clause or WCAG success criterion it comes from. The tool reports — it does not modify the file — and it cannot judge colour contrast, whether alternate text is meaningful, or whether the reading order matches the visual layout.
Reads the first 30 pages to detect scans and unmapped glyphs.