Chat with PDF Files in WordPress: Complete Guide

December 15, 2025 • 7 min read • Tutorial

Imagine uploading a 50-page contract to WordPress and asking "What are the cancellation terms?" and getting an instant, accurate answer. That's ChatProjects.

Why Chat with PDFs?

We're all drowning in documents. Employee handbooks, contracts, research papers, API documentation, client briefs—the list never ends.

Traditional search is useless for this. Ctrl+F only finds exact matches. You search for "vacation policy" but the document says "PTO guidelines." No results.

AI-powered document chat changes everything:

Semantic understanding – Ask questions in natural language, get relevant answers even when wording differs
Cross-document search – Upload multiple files, ask questions across all of them
Instant answers – Stop skimming 100-page PDFs for one piece of information
Context awareness – Follow-up questions understand what you asked before

73%

of knowledge workers say they spend too much time searching for information
— McKinsey Global Institute

Document AI isn't just convenient—it's a competitive advantage. Teams using AI for document search report saving 2+ hours per week on average.

How Document AI Works

Document AI uses a technique called RAG (Retrieval-Augmented Generation). Here's the simple version:

Upload

You upload a PDF (or Word doc, spreadsheet, code file). The system breaks it into small chunks.

Index

Each chunk gets converted into a "vector"—a mathematical representation of its meaning. These vectors are stored in a searchable index.

Search

When you ask a question, it's also converted to a vector. The system finds chunks with similar meaning—not just matching keywords.

Answer

The relevant chunks are sent to the AI along with your question. The AI reads them and gives you a direct answer.

Why "semantic" search matters: Traditional keyword search for "time off" won't find "PTO," "vacation," or "leave of absence." Semantic search understands these are all related concepts and finds all relevant content.

Step-by-Step Setup

Getting Document AI working in WordPress takes about 5 minutes. Here's exactly how to do it.

Step 1: Install ChatProjects

Download ChatProjects from chatprojects.com/free
In WordPress, go to Plugins → Add New → Upload Plugin
Upload the ZIP file and click Install Now
Click Activate

Step 2: Add Your OpenAI API Key

Document AI requires an OpenAI API key (it uses their Vector Stores feature).

Go to platform.openai.com
Navigate to API Keys
Click Create new secret key
Copy the key (you won't see it again)
In WordPress: ChatProjects → Settings → OpenAI
Paste your key and click Save

Tip: Your API key is encrypted with AES-256-CBC before storage. It never leaves your server—only the AI requests go to OpenAI.

Step 3: Create a Project

ChatProjects organizes your documents into "Projects." Each project is like a separate knowledge base.

Go to ChatProjects in your WordPress menu
Click New Project
Name it something descriptive (e.g., "HR Policies" or "Client Contracts")
Optionally add custom instructions (e.g., "Always cite the specific document and page when answering")

Step 4: Upload Your PDF

Open your project
Click the Upload button (paper clip icon)
Select your PDF file
Wait for processing (usually 5-30 seconds depending on size)
You'll see a confirmation when the file is indexed

Supported File Types

PDF Documents

DOC Word Files

XLS Spreadsheets

TXT Text Files

MD Markdown

CODE Source Code

Maximum file size: 512MB per file

Step 5: Start Asking Questions

Now the magic happens. Just type your question:

You

What is the refund policy for digital products?

According to Section 4.2 of your Terms of Service document, digital products are eligible for a refund within 14 days of purchase if the customer has not downloaded or accessed the product. Once downloaded, refunds are handled on a case-by-case basis and require approval from a manager.

Notice how the AI cites the specific section? That's because it actually reads and understands your document—it's not guessing.

Best Practices

Organize by Topic

Create separate projects for different document categories. "HR Policies," "Technical Docs," "Client Contracts"—this improves accuracy and keeps conversations focused.

Use Text-Based PDFs

Scanned documents (images of text) won't work well. If your PDF is a scan, run it through OCR software first (Adobe Acrobat or free tools like OCR.space).

Add Custom Instructions

Tell the AI how to behave: "Always cite document names and page numbers." "If you're unsure, say so." "Be concise." These instructions apply to every conversation in that project.

Ask Specific Questions

"What does this document say?" is too vague. "What are the payment terms for late invoices?" gets you a precise answer.

Real-World Use Cases

HR & Policy Search

Upload your employee handbook. Staff can ask questions like "How many sick days do I get?" or "What's the process for requesting remote work?" without bothering HR.

"We reduced HR policy questions by 60% in the first month."

Legal Contract Review

Upload contracts and ask about specific clauses: "What are the termination conditions?" "Is there an exclusivity clause?" "What's the liability cap?"

Save hours of contract review for standard questions.

Technical Documentation

Upload API docs, code documentation, or technical specs. Ask "How do I authenticate API requests?" or "What parameters does the /users endpoint accept?"

Perfect for onboarding new developers.

Research Synthesis

Upload multiple research papers or reports. Ask "What do these papers say about X?" or "Summarize the main findings across all documents."

Turn hours of reading into minutes.

Costs & Considerations

Document AI uses OpenAI's Vector Stores for indexing. Here's what to expect:

Component	Cost	Notes
Vector Storage	$0.10 / GB / day	Most users: pennies per month
Chat Messages	~$0.01-0.03 / query	Depends on document size retrieved
ChatProjects Free	$0	5 projects, full Document AI
ChatProjects Pro	$120 / year	Unlimited projects + extras

Real-world example: A 50-page PDF (~500KB) costs about $0.05/month to keep indexed. Even heavy users rarely exceed $1-2/month in vector storage costs.

Your data stays private: Documents are processed by OpenAI for vectorization, but ChatProjects uses the API with data retention disabled. OpenAI doesn't train on your data or store it beyond the immediate request.

Unlock More with Pro

The free version includes full Document AI with up to 5 projects. For power users, Pro adds:

Unlimited projects – Create as many document libraries as you need

AI image generation – Create visuals with DALL-E and Gemini

Model comparison – Compare Claude vs GPT side-by-side

Audio transcription – Convert meetings to searchable text

White-label – Remove ChatProjects branding for client sites

Start Chatting with Your Documents

Document AI is included free with ChatProjects. Get started in 5 minutes.

Download Free See Pro Features

Free includes 5 projects with full Document AI. No credit card required.

Frequently Asked Questions

Does the AI read my entire document?

Yes. When you upload a file, it's fully indexed. The AI retrieves relevant sections when you ask questions, so it can answer based on any part of the document.

Can I upload multiple files to one project?

Absolutely. Upload as many files as you need. When you ask questions, the AI searches across all documents in that project.

What about scanned PDFs?

Scanned PDFs (images of text) need OCR processing first. Tools like Adobe Acrobat or free services like OCR.space can convert them to searchable text.

Is my data secure?

Your documents are processed through OpenAI's API for vectorization. API data retention is disabled, meaning OpenAI doesn't store or train on your content. The plugin itself stores everything in your WordPress database.

How accurate is it?

Very accurate for factual retrieval from documents. The AI cites sources, so you can verify answers. It's not recommended for high-stakes legal or medical decisions without human verification.