Microsoft 365 Copilot is genuinely useful across your SharePoint and OneDrive content — until you point it at a scanned PDF and it comes back with nothing, or an answer that clearly isn't from the file. If Copilot can't read a scanned PDF, the reason is the same one that trips up every document AI tool, and there are a couple of clean fixes.
Copilot answers from content that has been indexed as text. A scanned or photographed PDF is an image of a page with no text layer, so there's nothing to index — and nothing for Copilot to retrieve. Here's why it happens in SharePoint specifically, and how to fix it.
Why Copilot skips scanned PDFs
Copilot draws on Microsoft Graph and the search index behind SharePoint and OneDrive. For a document to be answerable, its text has to make it into that index. Born-digital files — a Word export, a PDF from a design tool — index cleanly. Scanned files are pictures, so unless something has run OCR over them, they land in the index with little or no text.
Whether image OCR happens at all in SharePoint depends on your tenant's configuration, and it's inconsistent in practice — which is why the same scanned invoice or signed contract can be searchable in one library and invisible in another.
Quick check: open the PDF from SharePoint and try to select a sentence. If nothing highlights, it's image-only — that's why Copilot has nothing to say about it.
Fix 1 — Make the file searchable
The durable fix is to get real text into the file:
- OCR the PDF and re-upload a searchable copy, so its text lands in the index.
- Ask your SharePoint admin whether image/PDF OCR is enabled for the relevant libraries — this is a tenant-level setting, and turning it on makes newly added scans searchable going forward.
This is the right long-term move for a library that many people search. The downside is that it needs admin involvement and doesn't help you with a file you need an answer from right now.
Fix 2 — Read the file in the browser, with citations
When you just need the answer, you can read the document where it already lives. Sidenote is a browser reading assistant that reads SharePoint and OneDrive files read-only via Microsoft Graph — respecting the access you already have — and OCRs scanned PDFs so you can summarise and question them even when they never made it into the index.
Why it fits this exact problem:
- OCR on open. An image-only scan becomes readable and citable without waiting on a re-index or an admin setting.
- Cited answers. Every claim carries a scroll-to-source citation to the exact sentence, and unsupported claims are dropped server-side — which matters when the "document" is a policy or a contract someone will act on.
- Read-only and permission-aware. It reads the same files you can already open; nothing is written back to SharePoint. See how to summarise a SharePoint document for the full workflow.
Copilot vs an in-browser reader for scanned SharePoint files
| Microsoft 365 Copilot | In-browser reader (Sidenote) | |
|---|---|---|
| Scanned PDFs not yet OCR'd | Invisible — not in the index | OCRs on open |
| Depends on tenant OCR settings | Yes | No |
| Verify an answer | Varies | Click to the exact highlighted passage |
| Works on a single file now | Needs indexing first | Immediately, read-only via Graph |
| Best for | Broad answers across indexed content | Reading and citing a specific file |
The two aren't rivals — Copilot is built for organisation-wide answers across everything that's indexed, while an in-browser reader handles the specific, not-yet-searchable file in front of you. Plenty of teams use both.
Frequently asked questions
Does SharePoint OCR scanned PDFs automatically?
Sometimes — it depends on your tenant's configuration. Image/PDF OCR for search is a setting that may or may not be enabled, and even when it is, results vary. That's why a scanned file can be searchable in one library and invisible to Copilot in another. If a specific file isn't answerable, OCR is almost always the reason.
How do I make a scanned PDF readable by Copilot?
Get real text into it: OCR the file and re-upload a searchable copy, or have an admin enable image OCR for the library so future scans are indexed. Until the text reaches the search index, Copilot can't retrieve it.
Can I ask questions about a SharePoint file Copilot can't read?
Yes — open it in a browser reader like Sidenote that reads SharePoint and OneDrive read-only via Microsoft Graph and OCRs scanned PDFs on the spot, so you get a cited answer without waiting for the file to be indexed.