ANSWERS

Do AI models read PDFs?

Yes. Multimodal AI and OCR can read scanned or image-only PDFs, while support among web crawlers varies. A clean searchable text layer and an accessible HTML summary improve reliable discovery and extraction. ye5's GEO Web audit checks whether your pages and documents expose readable content to AI systems.

How do AI crawlers extract text from a PDF?

A text-based PDF stores its words as selectable characters, the same layer your browser's "Find" function searches. Extraction support varies by system: some crawlers pull that character layer much like an HTML page's body copy, and others handle documents differently or not at all. Where extraction does run, layout information is often lost along the way.

What happens when a PDF has no text layer?

A scanned document is a photograph of a page saved as a file. Image-only PDFs work the same way: pixels arranged to look like words, with nothing for software to select or copy. OCR tools and multimodal systems can still read scanned or image-only PDFs, while web crawler support for them varies. Adding a searchable text layer and publishing an accessible HTML summary makes the content easier to discover and extract.

Should you use HTML or PDFs for content you want AI to cite?

Prefer HTML pages for anything you want an AI system to quote or cite. This is the same machine-readability question What is GEO (Generative Engine Optimization)? work is built to answer: can a crawler parse your structure, not only your words. Tagged PDFs can preserve headings, tables and reading order, so conversion does not necessarily erase all structure. HTML stays the more reliable surface for these signals:

—Heading tags that mark section breaks and topic hierarchy
—List and table markup that separates parallel facts cleanly (see: Do lists and tables help AI extract my content?)
—Schema.org markup that names entities and defines claims (see: Does schema markup help AI visibility?)
—Individual page URLs, so a crawler can point to one answer instead of a whole file

ye5's GEO Web audit checks website access and readability, including whether key content is reachable as HTML. For the full picture of AI-readability across a site, see (see: How do I make my website readable to AI crawlers?).

When does a PDF still make sense?

Some documents work fine as PDFs: signed contracts, printable spec sheets, one-time compliance reports meant for a single download. The distinction is intent. Files people print or archive can stay PDFs, but a page written to answer a customer's question belongs in HTML, where crawlers read it cleanly. When the document has to stay a PDF, tag it, give it a searchable text layer, and publish an HTML summary beside it.

FAQ

Can OCR make a scanned PDF readable to AI?

OCR software adds a text layer by recognizing characters in the image, and the resulting text can then be extracted like any other file. Scan resolution and image quality affect how accurate that text layer turns out. Multimodal systems can also read the image content directly, though support among web crawlers varies.

Does turning a PDF into HTML content preserve everything?

The words carry over, but headings, tables, and embedded schema usually need rebuilding by hand. A straight text dump won't recreate them automatically.

Do image-heavy PDFs with captions get read?

Caption text extracts when it sits in a real text layer. Text baked into an image, like a chart label, needs OCR or a multimodal reader, and support for that varies by system.