Types of PDFs and AI Capabilities

PDF extraction is one of the most practical applications of AI. Whether you're processing invoices, research papers, or contracts, AI can save hours of manual copying and reformatting. The key is understanding what types of PDFs you're working with and what AI can do with each.

Three Types of PDFs

Not all PDFs are created equal. How your PDF was created determines how easily AI can extract data from it.

1. Native/Digital PDFs

These are PDFs created directly from digital sources - exported from Word, Excel, or generated by software. The text is actual text data, not an image.

Characteristics:

• You can select and copy text
• Text is searchable with Ctrl+F
• Tables have actual cell structure
• Smallest file sizes

AI Capability: Full text extraction with near-perfect accuracy.

2. Scanned PDFs with OCR

These started as paper documents that were scanned. If OCR (Optical Character Recognition) was applied, there's a text layer beneath the image.

Characteristics:

• Text may be selectable but with errors
• Quality depends on scan resolution
• May have skewed or rotated pages
• Medium to large file sizes

AI Capability: Good extraction, but may need cleaning up.

3. Image-Only PDFs

Scanned documents without OCR processing. The PDF is essentially a container for images.

Characteristics:

• Cannot select text at all
• No searchable content
• Often from older scanners or fax machines
• Largest file sizes

AI Capability: Requires vision capabilities (like GPT-4V or Claude). Works well for clear documents.

Quick Test: What Type is Your PDF?

Try this simple test on any PDF:

1. Open the PDF
2. Try to select some text with your mouse
3. Check the results:

Result	PDF Type	AI Extraction
Text selects cleanly	Native/Digital	Excellent
Text selects with gaps/errors	Scanned with OCR	Good
Nothing selects	Image-only	Requires vision AI

What AI Can Extract

Modern AI tools like ChatGPT and Claude can extract multiple types of structured data:

Understanding AI Limitations

AI extraction isn't perfect. Here's what to watch for:

Best Practices for PDF Preparation

Before uploading a PDF to AI, consider these optimizations:

For better results:

• Use high-resolution scans (300 DPI minimum)
• Ensure pages aren't skewed or rotated
• Remove unnecessary pages to save context
• Split very large documents into sections

Avoid these issues:

• Handwritten text (AI struggles with this)
• Extremely small fonts
• Complex multi-column layouts
• Watermarks over text

Key Takeaway

The first step in PDF data extraction is identifying your PDF type. Native PDFs give the best results, while image-only PDFs require vision-capable AI models. Understanding your document type helps you choose the right approach and set realistic expectations for extraction quality.

Next, we'll cover the practical steps of uploading PDFs to ChatGPT and Claude.