Local Knowledge Base

How to Chat With a Folder of PDFs Locally on Windows

September 2026 8 min read Percy Ng

The useful version of “chat with a PDF” is not chatting with one file at a time. It is being able to ask one question across an entire project folder and have AI find the relevant document for you — locally.

The folder problem

A project can easily contain dozens or hundreds of PDFs: contracts, reports, specifications, meeting packs and archived correspondence. Windows search can locate filenames and text, but it does not naturally answer questions that require meaning or context across several documents.

A local AI knowledge base adds semantic retrieval: instead of remembering the exact phrase, you ask the question you actually have.

How multi-document local AI works

Each document is parsed and divided into searchable passages. Those passages are represented in a local index. Your question is compared with that index, relevant passages are retrieved, and a local language model uses them to construct an answer.

Traditional searchLocal AI retrieval
Find “termination notice”“How much notice is needed to end each agreement?”
Find filenameFind relevant information across many files
Returns matching documentsCan synthesise an answer from retrieved passages

A sensible folder workflow

  1. Group documents by client, project or subject rather than indexing your entire drive blindly.
  2. Remove obsolete copies where possible so conflicting versions do not confuse retrieval.
  3. Add the folder to your local AI knowledge base.
  4. Let indexing complete before testing broad questions.
  5. Start with a question whose answer you already know to assess retrieval quality.
  6. For important answers, identify and open the source file.

Useful questions to try

  • Which documents mention a renewal date?
  • Summarise the decisions made across these project reports.
  • Where do our procedures discuss password resets?
  • Which contract contains the shortest termination period?
  • What changed between the older and newer project material?

Documents plus memory

A document library answers “what do my files say?” Persistent assistant memory addresses a different question: “what have we already discussed or decided?” Combining the two can make a personal assistant considerably more useful than a one-off PDF chat.

Build a private knowledge base with Beginza AI

Beginza AI is designed to combine local document retrieval and persistent context on Windows. The goal is not merely to open one PDF, but to make your own material useful as an ongoing private knowledge base.

Turn a document folder into something you can question. Try Beginza AI free during beta.

Download Beginza AI →

Frequently asked questions

Can I search hundreds of PDFs with local AI?

Yes, although indexing time and retrieval quality depend on the application, document size and hardware.

Will the AI change my original files?

A retrieval workflow normally reads and indexes files rather than modifying them. Check the behaviour of the specific application you use.

Should I index my whole C: drive?

Usually no. Curated folders produce a clearer knowledge base and reduce irrelevant retrieval.


About Beginza — Beginza builds privacy-first Windows software designed to keep useful work on your device. Explore Beginza.

PN

Percy Ng

Co-founder of Beginza. Builds privacy-first Windows tools and Beginza AI.