Summarize a PDF without sending it to the cloud

"Summarize this PDF" is one of the genuinely useful things AI does — turning a 30-page lease or a dense policy into five lines you can actually act on. But there's a catch nobody mentions in the button label: with most tools, summarizing means uploading your document to a server. For a marketing whitepaper, fine. For a contract, a diagnosis, or a financial statement, that's a lot to hand over for a paragraph of summary.

On newer iPhones, there's now a second option — the summary can happen on the device instead. Here's the trade-off, plainly.

Where the summary actually happens

When you summarize a document, the text has to reach a language model. There are two places that model can live:

• In the cloud. Your document (or big chunks of it) is sent to a company's servers, summarized there, and the result comes back. Fast and powerful, but your file left your phone — and what happens to it after depends entirely on that company's policy.
• On the device. The model runs locally using the iPhone's own hardware. The document never leaves. It can be a little slower and the model is smaller than a giant cloud one, but nothing is uploaded.

For sensitive paper, that difference is the whole ballgame.

How to tell which kind you're using

• Airplane mode is the honest test. Turn off networking and try to summarize. If it still works, it's running on your device. If it fails or hangs, it needed a server.
• Check whether an account is required. Cloud AI features usually sit behind a login.
• Read the privacy label and policy for language about processing your content on servers.

The trade-off, without spin

On-device summarizing is more private, but it isn't a free lunch:

	Cloud summary	On-device summary
Document leaves your phone	Yes	No
Works in airplane mode	No	Yes
Raw model power	Higher	Smaller, but capable
Requires a recent iPhone	No	Yes — needs the on-device model
Depends on a company's data policy	Yes	No — there's nothing to govern

If you're summarizing public documents and want the most powerful model, cloud is reasonable. If the document is yours and private, on-device is the safer default.

How Pocket PDF does it

Pocket PDF runs its summaries on your iPhone, on supported models, so the document never leaves the device. You get a summary in three lengths — Quick, Standard, or Detailed — and you can go further and ask the document a question, answered only from its own text, not from the open internet. All of it works in airplane mode, because none of it phones home.

That sits inside the same on-device toolkit as scanning, signing, redaction, and merging. Scanning, importing, and your library are free; Patron unlocks the toolkit as a single purchase across the Kraft family.

The honest limitation

An on-device model is smaller than the largest cloud models, so for extremely long or highly technical documents a cloud tool may produce a sharper summary — and the feature needs a recent enough iPhone to run at all. It's a real trade: a little raw capability in exchange for your document never leaving your hand. For the private paper most people actually need summarized, we think that trade is worth making, and it's the one Pocket PDF is built around.