ChatGPT vs Claude for Document Analysis: Which Is Better in 2025?

Quick Overview: ChatGPT vs Claude

File Handling Capabilities

ChatGPT File Upload

ChatGPT (with GPT-4) supports direct file uploads for Plus and Enterprise subscribers. It handles:

• PDFs with good text extraction
• Word documents (.docx)
• Text files and code files
• Images for analysis
• Spreadsheets (limited)

The catch: ChatGPT's free tier has very limited file upload capabilities. If you're on the free plan and need to upload large documents, you'll need a workaround like FileUploadGPT to split and send documents in chunks.

Claude File Upload

Claude 3 offers file upload on all tiers, including free. It supports:

• PDFs (text-based)
• Text and code files
• Images
• CSV files

Limitation: Claude's 10MB file limit is more restrictive than ChatGPT's 25MB. For larger files, you'll still need chunking solutions.

Analysis Accuracy Comparison

I tested both models on identical documents across several categories. Here's how they performed:

Legal Document Analysis

Test: 15-page commercial lease agreement

• ChatGPT: Identified 12 of 14 key clauses, missed 2 renewal-related provisions buried in appendices
• Claude: Identified 13 of 14 key clauses, better at connecting cross-references throughout the document

Winner: Claude (marginally)

Research Paper Summarization

Test: 30-page academic paper on machine learning

• ChatGPT: Excellent methodology summary, good at explaining technical concepts in plain language
• Claude: More thorough literature review summary, better at maintaining nuance

Winner: Tie (different strengths)

Code Review

Test: 2,000-line Python codebase

• ChatGPT: Found 8 potential bugs, excellent at suggesting optimizations, strong refactoring advice
• Claude: Found 7 potential bugs, better at understanding overall architecture, clearer explanations

Winner: ChatGPT (for pure code review)

For detailed code file upload instructions, see our guide on uploading large code files to ChatGPT.

Financial Report Analysis

Test: Company quarterly report (40 pages with tables)

• ChatGPT: Good number extraction, accurate ratio calculations
• Claude: Better at contextualizing numbers, caught more footnote details

Winner: Claude

Context Window: Why It Matters

The context window determines how much text the AI can "see" at once. This is crucial for document analysis.

What this means in practice: Claude can theoretically analyze longer documents in a single conversation. However, both models can experience "attention drift" on very long documents, where they lose track of information from the beginning.

For optimal results with documents over 50 pages, consider:

1. Breaking documents into logical sections
2. Using specific page references in your questions
3. Asking focused questions rather than broad ones

Learn more about managing large documents in our ChatGPT document analysis tips guide.

Best Use Cases for Each AI

Choose ChatGPT When:

• Code review and debugging - ChatGPT's code interpreter and programming knowledge edge out Claude slightly
• Quick PDF summaries - ChatGPT's PDF handling is very polished
• Mathematical analysis - Better at complex calculations and data manipulation
• You need plugins/GPTs - ChatGPT's ecosystem offers more integrations
• Image-heavy documents - ChatGPT handles mixed media better

Choose Claude When:

• Very long documents - The larger context window helps
• Legal and contract review - Better at finding nuances and cross-references
• Research synthesis - Stronger at maintaining context across lengthy analyses
• You're on a free plan - Claude offers more free-tier file uploads
• You need detailed explanations - Claude tends to be more thorough

Pricing Comparison (2025)

Best value for document analysis: If you're primarily analyzing documents and don't need other ChatGPT features (like DALL-E or custom GPTs), Claude's free tier offers better document capabilities. For power users who need both platforms, the paid tiers are identically priced.

If you want to maximize ChatGPT's free tier for document analysis, FileUploadGPT lets you upload large files without paying for Plus.

Final Verdict: Which Should You Use?

After extensive testing, here's my recommendation:

For Most Users: Use Both

Seriously. Each AI has strengths the other lacks. I use Claude for initial long-document analysis and contract review, then switch to ChatGPT for code-heavy work and when I need plugin integrations.

If You Must Choose One:

• Choose ChatGPT if: You work primarily with code, need the plugin ecosystem, or prefer a more polished interface
• Choose Claude if: You work primarily with long text documents, need free-tier file uploads, or do legal/academic analysis

The Free Tier Question

If you're trying to avoid paid subscriptions, Claude's free tier is more generous for document uploads. However, with FileUploadGPT, you can work around ChatGPT's free-tier limitations by chunking large documents automatically. This gives you access to GPT-4's analysis capabilities without the $20/month cost.