Chat With Your Documents Privately — No Cloud Upload Required
Query your PDFs, contracts, and research notes with AI — without your documents ever leaving your PC.
ChatGPT Can Read Your Documents — But It Also Keeps Them
ChatGPT's document upload feature is impressive. Drop in a PDF, a contract, or a research paper and you can ask questions about it, get summaries, extract tables, and have the content explained. The problem is that when you upload a document to ChatGPT, that document travels to OpenAI's infrastructure. It is processed there, it is stored there (for varying periods depending on your settings and plan), and it becomes part of the data OpenAI manages on your behalf. For casual users working with non-sensitive content, this is acceptable. For professionals working with client documents, legal files, financial records, or proprietary research, it is not.
CFAI provides the same document Q&A capability — ask a question, get a precise answer grounded in the document — using a fundamentally different architecture. Documents are indexed locally on your Windows PC using FAISS, a high-performance vector search library that runs entirely in-process. When you ask a question, CFAI identifies the most relevant passages using local semantic search and sends only those passages — plus your question — to the LLM. The full document is never transmitted. Combined with a local LLM via Ollama or LM Studio, not even the passages leave your device.
This distinction matters in practice. A lawyer who needs to query a contract does not want that contract on OpenAI's servers. A doctor reviewing patient documentation needs to stay within HIPAA boundaries. A competitive analyst working with unreleased product research cannot upload it to a public AI tool. CFAI makes document AI available to exactly these professionals, without the exposure that makes ChatGPT document upload unsuitable for their work.
AI Document Chat Tools — Privacy Architecture Comparison
| Tool | Local Processing | No Bot | Speaker ID | Real-time Translation | Cognitive Map | Price |
|---|---|---|---|---|---|---|
| CFAI ★ Recommended | ✅ | ✅ | ✅ | ✅ | ✅ | Free trial / From €7.99/mo |
| ChatGPT | ❌ | ✅ | ❌ | ❌ | ❌ | Free / Plus $20/mo |
| Claude.ai | ❌ | ✅ | ❌ | ❌ | ❌ | Free / Pro $20/mo |
| PrivateGPT | ✅ | ✅ | ❌ | ❌ | ❌ | Free (CLI self-hosted) |
| Khoj | ❌ | ✅ | ❌ | ❌ | ❌ | Free self-hosted / $12/mo cloud |
Why CFAI Is the Best Private Alternative for Document Chat
FAISS Local Indexing
Documents are indexed in-process using FAISS. No file is uploaded, no content transmitted during indexing. Your documents stay on your PC from start to finish.
Minimum Data Transmission
Only the retrieved passage relevant to your question is sent to the LLM — never the full document. Combined with a local LLM, zero data leaves your device.
Documents + Meeting Transcription
CFAI goes beyond document chat. It also transcribes your meetings locally and connects document context to live conversation — a capability no document-only tool offers.
BGE Reranking for Precision
CFAI uses BGE reranking to improve retrieval precision — selecting the most relevant passages before they're sent to the LLM. Better answers, less hallucination.
No Q&A History Storage
Your questions and document answers are not stored on any external server. CFAI does not log your document queries or use them to train models.
No Technical Setup Required
Unlike PrivateGPT or self-hosted Khoj, CFAI is a Windows desktop app. No command line, no Docker, no server setup. Install and use immediately.
Real-Time During Meetings
Query your document library during a live meeting call. CFAI retrieves relevant passages from your files in real time while you are on a call.
Free Trial
Start with the free trial to test document Q&A on your own files before choosing a plan. No credit card required.
How to Chat With Your Documents Privately Using CFAI
Install CFAI on Windows
Download from cfai.io. No cloud account required. Free trial with full document AI features. Runs on Windows 10/11.
Add Your Documents
Import your PDFs, Word files, or text documents. CFAI indexes them locally using FAISS — no upload, no external API call during indexing.
Ask Questions
Type a question about your documents. CFAI retrieves the relevant passage locally and sends only that — plus your question — to the LLM for a grounded answer.
Use During Meetings Too
Open CFAI during a Teams, Zoom, or Google Meet call. Query your document library in real time while speaking — context-aware AI assistance without switching apps.
Frequently Asked Questions
How does CFAI avoid uploading my documents?
CFAI uses FAISS for local vector indexing. When you add a document, CFAI reads it in-process on your PC and builds a searchable index locally. No file content is transmitted during this step. When you ask a question, CFAI performs semantic search locally to find the relevant passage, then sends only that passage plus your question to the LLM. The full document never leaves your device.
Is there a way to chat with PDFs without ChatGPT?
Yes — CFAI provides AI document chat without uploading to ChatGPT or any cloud service. Other local options include PrivateGPT (CLI-based, technical setup required) and Khoj (self-hosted). CFAI is the only option that also includes meeting transcription, real-time translation, and a Cognitive Map — all running locally on Windows.
Can I use CFAI for confidential legal or medical documents?
CFAI's local-first architecture makes it well-suited for professionals handling sensitive documents. Legal files, medical records, financial data — documents you cannot upload to ChatGPT can be processed locally with CFAI. As with any tool, confirm that your use satisfies your professional obligations. But CFAI's architecture eliminates the primary privacy exposure that makes cloud document AI inappropriate for these use cases.
How does CFAI compare to PrivateGPT for document privacy?
Both CFAI and PrivateGPT are local-first. PrivateGPT is a CLI tool requiring technical setup, Docker knowledge, and manual model configuration. It has no meeting transcription, no GUI, and no Windows installer. CFAI is a native Windows desktop app — install and use immediately, no command line, with meeting transcription, speaker diarization, real-time translation, and Cognitive Map included alongside local document chat.
What file types does CFAI support for document chat?
CFAI supports PDF, Word (.docx), and plain text files. You can add multiple documents and query across them simultaneously. CFAI also includes local OCR — you can screenshot any on-screen content and have it added to your searchable knowledge base automatically.
Chat With Your Documents — Privately
Download CFAI free and start querying your PDFs and documents with AI — without uploading them to ChatGPT or any cloud service.