Tagged PDF Validator
Check whether a PDF is tagged (has a structure tree), how many tags it has, and whether key accessibility prerequisites (lang attribute, MarkInfo) are set.
1. Upload your file
How does the Tagged PDF Validator work?
Check the structural prerequisites of a tagged (accessible) PDF. The tool walks the document Catalog and reports: (1) whether /MarkInfo /Marked is true (the assertion that the PDF is tagged), (2) whether a /StructTreeRoot exists, (3) how many tags the structure tree contains, (4) whether /Lang is set (a language identifier required by PDF/UA), and (5) whether /ViewerPreferences /DisplayDocTitle is true (per PDF/UA-1). A pass/warn score summarises the result. Use this as a first-pass before deeper Section 508 validation; it identifies the basic plumbing missing in untagged or partially-tagged documents.
🔒 Security & Privacy
All processing happens on your device. Your files never leave your browser, never touch our servers, and are not stored anywhere. Close the tab and the file is gone.
📱 Use it on any device
Works in any modern browser — Mac, Windows, Linux, iPhone, Android, and tablets. No installation, no app to download. Just open the page and start.
⚡ Quick & easy
Drag, drop, click. Most files process in seconds, not minutes. No watermarks added to your output, no per-day limits, and the tool always shows the result before asking you to download.
🎁 Always free, no signup
Free to use, every time. No account creation, no email required, no “trial” that converts to a paid plan. We make money from ads so you don’t have to pay.