What you will be able to do
- Decide whether a document belongs in a single chat or in a project's knowledge base
- Predict what Claude can and cannot read from an uploaded or Drive-linked file
- Choose between a static upload and a Drive-synced document for content that changes
- Diagnose and fix wrong answers caused by outdated project knowledge
Key concept
Static upload vs. synced source — An uploaded file is a fixed copy that stays as it was until someone replaces or removes it. A Google Doc added through the Drive connector syncs from Drive, so Claude sees the current version. Whether knowledge stays accurate depends mostly on which of the two you picked.
1.Chat attachment or project knowledge?
Before you upload anything, decide where it should live. There are two places. You can attach a file to one chat, using the "+" button and "Add files or photos" or by dragging it into the window. Or you can add it to a project's Files section, which is the project knowledge base. The upload documentation describes the difference in one line: files go either to individual chats or to a project's Files section "for persistent reference across conversations."
Project knowledge reaches every chat in that project. Whatever you upload to the knowledge base on the right side of the project page is used in all of the project's chats. A file attached to a single chat does not travel the same way, even when that chat is inside a project. The project documentation is explicit: chats in a project do not share context with each other unless the information has been added to the project knowledge base.
So use a chat attachment for a one-off question, such as a contract you want summarised once. Use project knowledge for material many conversations need, such as a style guide, a product catalogue or a policy handbook.
Checkpoint 1 of 5· Check yourself
A user attaches a product spec to one chat inside their "Launch" project. The next day, in a new chat in the same project, Claude doesn't know the spec. Why?
Chats inside a project don't share context. Only content added to the project knowledge base reaches every chat in the project.
“Context is not shared across chats within a project unless the information is added into the project knowledge base.”Source: support.claude.com
2.What Claude actually reads from a file
Uploading a file does not mean Claude sees everything in it. The supported document types are PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON and XLSX. Supported image formats are JPEG, PNG, GIF and WebP. XLSX has a condition: you must turn on code execution and file creation in your account before you can upload it. A chat accepts up to 20 files, and Drive files added to a chat must all fit within the conversation's context window.
How much Claude can read depends on the file type. Text inside images and charts is lost more often than people expect.
| Source | What Claude processes |
|---|---|
| PDF, 100 pages or fewer | Text and visual elements (images, charts, graphics) |
| PDF, 101–1000 pages | Text only; visual elements not analysed |
| PDF over 1000 pages | Cannot be uploaded ("Uploaded file is too large") |
| Non-PDF documents (e.g. DOCX) | Text only; embedded images not read |
| Google Drive file | Text content only; embedded images not processed |
The Drive row comes from the Google Workspace connector documentation, which says the same thing: when Claude reads a Google Drive file, it extracts text content only. If the knowledge lives in a diagram, add that content as text or as a PDF of 100 pages or fewer. For very large documents, the guidance is to split them into smaller sections so they stay within limits.
Checkpoint 2 of 5· Check yourself
A project's knowledge includes a DOCX onboarding guide. Its org chart is an embedded image. A user asks Claude who reports to the CFO. What should they expect?
For non-PDF documents Claude extracts text only, so the embedded image is not read. A supported file type does not mean every element in the file is processed.
“For non-PDF documents: Claude extracts text only from these files.”Source: support.claude.com
3.Drive-synced documents for content that changes
An uploaded file is a fixed copy. If the original on your laptop changes, the copy in Claude stays the same. For a document that changes often, Google Drive is the better route. Google Docs added to chats and projects through the Drive connector sync directly from Drive, so Claude works with the latest version.
That restriction is easy to miss. Adding Drive files to project knowledge works only in private projects, and the documentation states that the option "will be disabled for shared projects." In a private project you open Files, click "+", choose Drive, then search your recent documents or paste the document's URL. The document is then added to the project knowledge. To add a Drive document to a single chat instead, click the plus sign and choose "Add from Google Drive."
Checkpoint 3 of 5· Put it in order
Put the steps for adding a Google Doc to a private project's knowledge in order.
- 1.Click the "+" button to add files
- 2.Select "Drive"
- 3.Search your recently accessed documents or paste the document's URL
- 4.Open your project and find the Files section
You start in the project's Files section, open the add menu, choose Drive as the source, then pick the document. It then becomes part of the project knowledge.
“Your document is added to your project knowledge for Claude to access when chatting in that project.”Source: support.claude.com
Link the handbook through the Drive option so it syncs and Claude always sees the current version. A normal upload works for the annual report: since it never changes, a fixed copy never goes stale. If the project were shared, the Drive option would be disabled, so someone would have to replace the handbook upload by hand whenever it changes.
Sources3
4.Stale knowledge: when the wrong answer comes from the file
Claude treats everything in project knowledge as context for the project's chats, including outdated files. If someone uploaded a pricing sheet months ago and it has since been replaced, Claude can keep quoting it. The problem is the old document, not the model. The fix is to change the knowledge base, and the documentation confirms you can add and remove project content at any time.
Large knowledge bases make this harder to notice. When project knowledge gets close to the context window limit, Claude switches to RAG mode on its own. Instead of loading everything, it searches and retrieves only the most relevant information. You can tell when this is happening because you'll see Claude use a project knowledge search tool. Retrieval picks the passages that best match the question, and nothing guarantees those come from the newest file. The RAG guidance also says well-named files help Claude retrieve the right information, so a clear name such as 'Pricing 2026 – current' makes Claude more likely to pull the right file.
In a shared project, permissions decide who can do the cleanup. Members with Can view can see project contents, knowledge and instructions and can chat, but cannot edit the project. Members with Can edit can modify project instructions and knowledge. A viewer who spots a stale file has to ask an editor to remove it.
Checkpoint 4 of 5· Check yourself
A member with "Can view" access to a shared project notices Claude quoting a superseded pricing sheet from the project knowledge. What can they do about the file directly?
Can view members cannot change project knowledge. Only someone with Can edit can remove or replace the outdated file.
“Can view: Members can see project contents, knowledge, and instructions, and chat within the project, but cannot edit it.”Source: support.claude.com
Checkpoint 5 of 5· Exam question
At an Enterprise organization, no one has enabled connectors yet, and an employee tries to connect Google Drive. What must happen before the employee can authenticate?
Correct answer: D — An Owner or Primary Owner must first enable the connector organization-wide.
- A. Incorrect. There is no support-ticket whitelisting process; the control point is an org-level toggle set by an Owner or Primary Owner.
- B. Incorrect. Switching account types is irrelevant; the organization admin simply needs to enable the connector.
- C. Incorrect. No separate marketplace add-on installation is a prerequisite for the Drive connector.
- D. Correct. On Team and Enterprise plans, an Owner or Primary Owner must enable connectors org-wide before members can authenticate their own accounts.
Exam traps
Each one states something that sounds right. Open it to see what is actually true.
1.A file attached to any chat inside a project is automatically available to every other chat in that project.Why is that wrong?
Only content added to the project knowledge base reaches every chat in the project. A file attached to one chat stays in that chat.
Covered in Chat attachment or project knowledge?
2.You can keep a shared project current by linking its documents through the Google Drive connector.Why is that wrong?
Adding Drive files to project knowledge only works in private projects. In shared projects the option is turned off, so their knowledge has to be maintained by uploading files.
3.If Claude can open a Google Drive file, it can also interpret the diagrams and images inside it.Why is that wrong?
Claude extracts only the text from a Drive file. Images embedded in the document are not processed.
Covered in What Claude actually reads from a file
Sources
Every claim above is drawn from one of these pages, quoted as it was written on the date shown.
- 1.
“Files can be uploaded to individual chats or uploaded to a project's Files section for persistent reference across conversations.”
↩︎ Chat attachment or project knowledge?“You must enable code execution and file creation in your account to upload XLSX files.”
↩︎ What Claude actually reads from a file“consider dividing them into smaller sections to stay within limits”
↩︎ What Claude actually reads from a file“For PDFs from 101 to 1000 pages, Claude processes text only and doesn't analyze visual elements.”
↩︎ Prediction“For non-PDF documents: Claude extracts text only from these files.”
↩︎ Checkpoint - 2.
“Anything you upload to this space will be used across all of your chats within that project.”
↩︎ Chat attachment or project knowledge?“Context is not shared across chats within a project unless the information is added into the project knowledge base.”
↩︎ Exam trap 1“Context is not shared across chats within a project unless the information is added into the project knowledge base.”
↩︎ Checkpoint - 3.
“The files must fit within the conversation's context window.”
↩︎ What Claude actually reads from a file“Google Docs added to chats and projects sync directly from Google Drive, so you're always working with the latest version.”
↩︎ Drive-synced documents for content that changes“Google Docs added to chats and projects sync directly from Google Drive, so you're always working with the latest version.”
↩︎ Key concept“This option will be disabled for shared projects.”
↩︎ Exam trap 2“When Claude reads a Google Drive file, it extracts text content only.”
↩︎ Exam trap 3“The Google Drive connector is only available when adding to Files in private projects.”
↩︎ Prediction“Your document is added to your project knowledge for Claude to access when chatting in that project.”
↩︎ Checkpoint - 4.https://support.claude.com/en/articles/11473015-retrieval-augmented-generation-rag-for-projectsOfficial docs
“Add and remove content at any time”
↩︎ Stale knowledge: when the wrong answer comes from the file“Claude intelligently searches and retrieves only the most relevant information needed to answer your questions.”
↩︎ Stale knowledge: when the wrong answer comes from the file“Well-named files help Claude understand and retrieve the right information more effectively.”
↩︎ Stale knowledge: when the wrong answer comes from the file - 5.
“Can edit: Members can modify project instructions and knowledge”
↩︎ Stale knowledge: when the wrong answer comes from the file“Can view: Members can see project contents, knowledge, and instructions, and chat within the project, but cannot edit it.”
↩︎ Checkpoint