Google does not index PDFs as PDFs — it converts them to HTML first, then ranks the conversion. That confirmation came from Google engineers Martin Splitt and John Mueller on the Search Off The Record podcast, and it settles a long-running question for publishers who host white papers, menus and forms as PDF files.

How does Google actually process a PDF?

Splitt, who works on Google's rendering and indexing systems, explained the mechanics in detail. A converter component sits between rendering and indexing, and it handles multiple file formats.

"What we are doing in Search is we have a component called a converter. And the converter component is part of what happens in indexing. It happens right after rendering and right before something potentially makes it into the index," Splitt said.

He listed the formats the converters handle: rich text files, document files, Excel sheets and "Lotus Notes documents for some reason." The PDF converter produces an HTML version, and the rest of Google's pipeline works almost exclusively with HTML.

Images inside PDFs are the exception. Splitt was candid about the limits of his own knowledge here.

"I think we understand there is an image, but I don't think we can actually process it like a normal image for image search. But that might change or might have changed; that's my current understanding of how that pipeline works," he said.

The reason: Google's image pipeline normally relies on image URLs, and an image embedded in a PDF has no URL to hand over.

Takeaway: your PDF text gets indexed; the images inside it probably do not — for now.

Do links inside PDF files pass value?

Yes. Mueller connected the dots directly: "So basically when Google sees a PDF file, it converts it into something that it has more practice with, kind of a web page. And I guess that's also why things like links also work in PDF files."

Splitt confirmed: "Yep. Because we convert it into an HTML page and then the rest of our systems are like, 'I know how to deal with an HTML page,' and they just do their stuff."

He added that the conversion stays "as true as is possible to that original format," which is why embedded links survive the process and behave like normal HTML links.

Takeaway: a link in a PDF is a link, full stop.

What are the size limits?

Mueller asked the question himself, admitting the limits of Google's public knowledge: "I realize some of these things maybe we just don't know the details, so we're kind of trying to extrapolate from what we do know."

Splitt's answer was hedged. PDFs likely get a larger crawl limit than standard web pages, similar to how Google treats videos and images, but he did not know the specific number. He believes normal HTML limits apply once the PDF is converted. He also warned that any current limit could change if Google detects publishers moving to larger PDFs.

Takeaway: no hard figure exists, and Google left the door open to changing it.

Can PDFs rank in AI Mode?

Yes, and for the same reason they rank in regular search: the HTML conversion gets indexed like any other document. Mueller added: "So they can also appear in AI overviews, AI mode, all of those things."

One condition matters. Some PDFs are essentially images — scanned documents with no machine-readable text. Splitt offered a practical test: if you can highlight and copy the text from the PDF into a text file, Google can convert it and rank it.

Takeaway: selectable text is the bar; scanned pages likely fail it.

Should marketers publish PDFs at all?

Splitt said yes, when the format earns its place — print-specific layouts, forms, or a holiday lodge's registration form, for example. "Obviously HTML is a really flexible format and I prefer that, but if you have a PDF for whatever reason, go for it," he said, adding that a restaurant uploading its print-ready menu as a PDF beats having no menu online at all.

Mueller took a pragmatic line. A PDF menu beats no menu, but a normal web page beats a PDF menu because it is easier to interact with. His advice for site owners was blunt: "If you have something that you can put into HTML and it's just the same as your PDFs, that makes everything a little bit easier."

That closing point reframes the whole discussion. PDFs can rank, their links count, and AI Mode surfaces them — but every advantage Google described comes from the HTML conversion, not the PDF itself. For content that works in either format, the engineers' own preference points one way.