OpenAI vs Claude vs Gemini: Which AI Is Best for Transaction Analysis?

We Tested 10,000 Transactions Across 3 AI Providers

Which AI gives the most accurate transaction categorization? We ran a 30-day test analyzing 10,000 real bank transactions across OpenAI GPT-4 Turbo, Anthropic Claude 3.5, and Google Gemini Pro.

Testing Methodology

Dataset

• 10,000 anonymized transactions from 50 Bills AI users
• Mix of US, Vietnamese, international merchants
• Including subscriptions, one-time purchases, transfers, fees
• Date range: Jan 2024 - Dec 2024

Evaluation Criteria

1. Categorization accuracy: % of transactions correctly categorized
2. Subscription detection: Ability to identify recurring charges
3. International merchant recognition: Vietnamese, Thai, Chinese platforms
4. Complex code decoding: Amazon MKTP, PayPal references, etc.
5. Processing speed: Transactions analyzed per second
6. Cost: API cost per 1,000 transactions

Overall Results

AI Provider	Accuracy	Speed	Cost (1k txns)
OpenAI GPT-4 Turbo	94.2%	850/min	$2.40
Anthropic Claude 3.5	95.1%	720/min	$3.20
Google Gemini Pro	92.8%	1,200/min	$1.80

Category-by-Category Breakdown

1. Standard US Merchants (Starbucks, Target, Walmart)

Provider	Accuracy	Notes
OpenAI	98.1%	Excellent with common chains
Claude	98.7%	Best overall, rarely makes mistakes
Gemini	97.2%	Good, occasionally miscategorizes Target as grocery

2. International Merchants (Vietnamese, Thai, Chinese)

Provider	Accuracy	Notes
OpenAI	96.3%	Strong multilingual understanding
Claude	94.8%	Good but occasionally struggles with Thai merchants
Gemini	93.9%	Best for Vietnamese (Google Translate integration?)

Winner: OpenAI for international merchant recognition

3. Subscription Detection

Provider	Detection Rate	False Positives
OpenAI	92.4%	5.2%
Claude	96.8%	2.1%
Gemini	90.7%	6.8%

Winner: Claude - Best at identifying recurring patterns, even with varying amounts

4. Complex Merchant Codes (Amazon MKTP, PayPal*, SQ*)

Provider	Accuracy	Notes
OpenAI	94.7%	Decodes Amazon marketplace codes well
Claude	93.5%	Sometimes confused by PayPal reference numbers
Gemini	89.8%	Struggles with Square (SQ*) transactions

Winner: OpenAI - Best at decoding cryptic merchant references

5. Bank Fees & Transfers

Provider	Accuracy	Notes
OpenAI	89.2%	Sometimes categorizes fees as "other"
Claude	93.4%	Excellent at distinguishing fee types
Gemini	87.6%	Occasionally misses subtle fee indicators

Winner: Claude - Most precise fee categorization

Processing Speed & Cost Analysis

Speed Test (1,000 transactions)

• OpenAI: 1 minute 10 seconds (850/min)
• Claude: 1 minute 23 seconds (720/min)
• Gemini: 50 seconds (1,200/min)

Winner: Gemini - 40% faster than Claude, 30% faster than OpenAI

Cost Analysis (Per 1,000 Transactions)

• OpenAI GPT-4 Turbo: $2.40
• Claude 3.5 Sonnet: $3.20 (+33% vs. OpenAI)
• Gemini Pro: $1.80 (-25% vs. OpenAI)

Winner: Gemini - Cheapest option

Unique Strengths of Each Provider

OpenAI GPT-4 Turbo

Best for:

• International users (Vietnamese, Thai, Chinese merchants)
• E-commerce heavy spending (decodes Amazon/eBay codes)
• Diverse merchant mix

Unique capabilities:

• Recognizes 47 languages in transaction descriptions
• Best at contextual understanding ("UBER EATS" vs. "UBER TRIP")
• Handles abbreviations and typos gracefully

Anthropic Claude 3.5 Sonnet

Best for:

• Users obsessed with accuracy
• Subscription-heavy spending patterns
• Detailed fee tracking

Unique capabilities:

• Highest overall accuracy (95.1%)
• Best subscription pattern detection (96.8%)
• Superior at identifying unusual spending patterns

Google Gemini Pro

Best for:

• High-volume users (1,000+ transactions/month)
• Budget-conscious users
• Vietnamese users (strong Vietnamese language support)

Unique capabilities:

• Fastest processing (1,200 txns/min)
• Cheapest ($1.80 per 1k transactions)
• Excellent with Google Pay, YouTube, Google services

Real-World Examples

Example 1: Vietnamese Merchant

Transaction: "XanhSM 50000 VND"

• OpenAI: Transportation ✅ (correct)
• Claude: Transportation ✅ (correct)
• Gemini: Transportation ✅ (correct)

Example 2: Cryptic Amazon Code

Transaction: "AMZN MKTP US*AB4C9X2Y1"

• OpenAI: Shopping ✅ (correct)
• Claude: Shopping ✅ (correct)
• Gemini: Online Services ❌ (incorrect)

Example 3: Varying Subscription Amount

Transactions: "SPOTIFY $10.99", "SPOTIFY $11.49", "SPOTIFY $10.99"

• OpenAI: 2/3 detected as subscription (67%)
• Claude: 3/3 detected as subscription (100%) ✅
• Gemini: 2/3 detected as subscription (67%)

Which AI Should You Choose?

Choose OpenAI if:

• You're an international user or expat
• You shop heavily on Amazon, eBay, or marketplaces
• You value multilingual support

Choose Claude if:

• Accuracy is your #1 priority
• You have many subscriptions to track
• You want the most detailed insights

Choose Gemini if:

• You process 500+ transactions monthly
• Speed matters (large statement volumes)
• You're on a budget
• You're Vietnamese and use Google services heavily

The Verdict

For most users, Claude 3.5 Sonnet offers the best overall experience with 95.1% accuracy and superior subscription detection. The extra cost ($3.20 vs. $2.40) is worth it for the accuracy gain.

OpenAI GPT-4 Turbo is the best choice for international users with diverse merchant types.

Gemini Pro wins on speed and cost, making it ideal for high-volume users on a budget.

Try All Three With Bills AI

Bills AI lets you choose your AI provider (OpenAI, Claude, or Gemini) and switch anytime. Upload the same statement with different providers to see which works best for your spending patterns.