To ask questions about a PDF on an iPhone with no connection, you need an app that runs its language model on the phone. Save the PDF locally, install the app and its model while you’re still online, then confirm it works in Airplane Mode before you rely on it. Apple’s built-in options and Siri’s ChatGPT hand-off are not guaranteed to stay offline, so they aren’t the safe default.
Which routes are actually offline?
“Without internet” only holds if the model that reads your PDF and answers your question runs on the phone. Anything that sends the file or your prompt to a server fails that test. The table sorts the routes by what their own documentation says.
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| 1 |
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Apple iPhone 14, 128GB, Midnight - Unlocked (Renewed) | $300.00 | Buy on Amazon |
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Apple iPhone 16, 128GB, Pink - Unlocked (Renewed) | $587.99 | Buy on Amazon |
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Apple iPhone 16e, 128GB, Black - Unlocked (Renewed) | $387.73 | Buy on Amazon |
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| Route | What the source says | Offline? | Check first |
|---|---|---|---|
| AI PDF Reader: On-Device | Its App Store listing advertises PDF Q&A that works offline once a model is installed. It places scanned-PDF OCR in Pro. | Claimed by the developer, after setup | Model download, device and iOS requirements, Pro cost, file-size limits |
| DocuMind: Offline PDF AI Chat | Its App Store listing advertises offline Q&A, PDF and scanned-document import, and citations that jump to the source page. It states iOS 18 or later. | Claimed by the developer | Device requirements, model storage, purchase terms, OCR behavior |
| Shortcuts with Apple Intelligence | Apple’s iOS 26 features guide says shortcuts can “extract information from a PDF.” | Not guaranteed | Device, language, region, OS support, whether the action suits question-and-answer use |
| Siri with ChatGPT | OpenAI says Siri will always ask permission before sending a file to ChatGPT. | No | Whether sending the file to a cloud service is acceptable |
| Apple Books | Apple documents opening, saving and marking up PDFs. | Yes for reading, but no Q&A | Use it only to store and annotate the file |
The offline claims for the two apps come from the developers’ own listings. Neither listing is independent validation, and both listings say their privacy labels are developer-provided and not verified by Apple. Each also had too few ratings for an App Store rating overview when the pages were checked. This article doesn’t report hands-on tests of either app.
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Apple’s guide to Apple Intelligence and privacy on iPhone says some requests are processed on the device. It also says that “for more complex requests that require more computational capacity, Apple Intelligence can use Private Cloud Compute.” Private Cloud Compute needs a network connection. A Shortcuts action that pulls information out of a PDF may therefore work offline for a simple request and still need a connection for a harder one. Apple doesn’t promise either outcome for every case.
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The Siri and ChatGPT route is a different privacy choice
Siri can pass a document to ChatGPT, but only after you approve the transfer. OpenAI also says that processing and storage depend on whether you’ve connected an account and on your settings. Use this route when a cloud service is fine for the document. Don’t use it for a strict offline need.
Step-by-step: set up and verify an offline PDF workflow
- Save the PDF to the iPhone. Download it so it exists in Files or Books and not just in a browser tab or cloud link. Books can open and save PDFs and supports markup, but Apple’s guide doesn’t describe AI questions there.
- Pick an app that explicitly describes on-device processing. Read its current listing for minimum iOS version, device requirements, and whether a model must be installed first.
- Prepare while online. Install the app and download any model it needs. AI PDF Reader: On-Device says its model must be installed before offline use.
- Import the PDF. For a scan, confirm OCR is supported and that your plan includes it (see below).
- Ask a specific question. For example: “What is the payment deadline, and which page states it?” or “List the three eligibility conditions and show where each appears.” The DocuMind listing itself suggests prompts like “Summarize this,” “What’s the key idea?” and “When is the deadline?”
- Test in Airplane Mode. Switch it on, make sure Wi-Fi and cellular data are off, reopen the app and PDF, and repeat a harmless question. Do this with a non-sensitive file first, and before you travel or lose signal.
- Verify the answer against the page. Open the cited passage. If the app gives no source location, search the PDF yourself before acting on the answer.
Scanned PDFs need text recognition
A scanned PDF is a set of page images. Question answering only works if the app can recognize the text first. AI PDF Reader: On-Device lists scanned-PDF OCR under Pro, and DocuMind advertises scanned-document import. Confirm the exact support and any plan requirement before you depend on either. If the app returns nothing for a scan, missing OCR is the likeliest cause.
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Check answers, especially the high-stakes ones
DocuMind advertises citations that jump to the source page and highlighted text, which makes checking quick. That is a listed feature, not a measure of accuracy. Treat dates, amounts, legal wording and instructions as unconfirmed until you’ve read the passage yourself. Claims such as “100% offline” or “never hallucinate” in a listing are the developer’s words. No independent accuracy or speed figures for these apps were established.
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- Strict offline operation after setup, tested in Airplane Mode.
- Model download size and the storage it takes on your iPhone.
- Scanned-PDF OCR and which paid tier unlocks it.
- Minimum iOS version and supported devices.
- Page citations or highlighted sources.
- Limits on document size.
- Whether the file or your question can leave the phone.
Pricing, versions, requirements and regional availability change, so check the live listing and Apple’s current documentation before you buy.
Quick Recap
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