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.
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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.
Frequently asked
For heavier PDF workflows
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