Make any PDF accessible.

Tag untagged PDFs to the PDF/UA-1 standard — headings, paragraphs, lists, tables, figures and artifacts — with heuristics plus an optional vision model. Review each file, or tag a whole batch in one pass.

Documents Choose PDFs or drop them here Select one or more files — Ctrl/Cmd-click or Shift-click to multi-select

Re-tag documents that already have tags (existing tags are stripped first) Tag immediately without reviewing (recommended for batches)

Tagging engine Heuristics — built-in detectors, optionally refined by a vision model (below) OpenDataLoader — PDF structure parser: auto-tagging & reading order (needs Java 11+) YOLO — trained layout detector: element boxes & reading order from a vision model (needs PyTorch + Ultralytics)

Vision model — optional, any OpenAI-compatible endpoint Use a vision model to refine roles, reading order and tables

Base URL Model

API key

Also generate short alt text for figures Use LLM only — let the model build the entire tag tree (structure, reading order, element boxes) from each page image, instead of refining heuristics Structure depth

Document options

Language Title