OpenAI vs Anthropic: Real Cost Comparison 2025

Comparison 5 min read • December 4, 2025

At first glance, OpenAI is cheaper: GPT-4o costs $2.50/1M input tokens vs Claude Sonnet at $3/1M. That's a 20% price advantage for OpenAI.

But price per token doesn't tell the full story. Token efficiency—how many tokens each model consumes to complete the same task—reveals the real cost winner.

The Pricing Breakdown

Model	Input ($/1M)	Output ($/1M)	Best For
GPT-4o	$2.50	$10.00	General purpose, fast responses
GPT-4o-mini	$0.15	$0.60	Classification, extraction, simple tasks
Claude 3.5 Sonnet	$3.00	$15.00	Code generation, long-form writing
Claude 3 Haiku	$0.25	$1.25	Fast responses, simple tasks

But Token Efficiency Changes Everything

Here's the surprising finding from our analysis of 10,000 production requests:

Test #1: Summarization (500-word article → 50-word summary)

GPT-4o:
  Input: 650 tokens (prompt + article)
  Output: 72 tokens (summary)
  Total cost: (650 × $2.50/1M) + (72 × $10/1M) = $0.00235

Claude Sonnet:
  Input: 620 tokens (more concise prompt needed)
  Output: 58 tokens (terser summary style)
  Total cost: (620 × $3.00/1M) + (58 × $15/1M) = $0.00273

Winner: GPT-4o (16% cheaper for summarization)
            

Test #2: Code Generation (Python function from description)

GPT-4o:
  Input: 180 tokens (function description)
  Output: 420 tokens (code + explanation)
  Total cost: (180 × $2.50/1M) + (420 × $10/1M) = $0.00465

Claude Sonnet:
  Input: 180 tokens
  Output: 380 tokens (more concise code)
  Quality: 8% higher first-run success rate
  Total cost: (180 × $3.00/1M) + (380 × $15/1M) = $0.00624

Winner: GPT-4o (25% cheaper) but Claude has higher quality
            

Test #3: Long-Form Content (1,500-word blog post)

GPT-4o:
  Input: 250 tokens (brief + outline)
  Output: 2,100 tokens (verbose style)
  Total cost: (250 × $2.50/1M) + (2,100 × $10/1M) = $0.02163

Claude Sonnet:
  Input: 250 tokens
  Output: 1,850 tokens (more concise, same quality)
  Total cost: (250 × $3.00/1M) + (1,850 × $15/1M) = $0.02850

Winner: GPT-4o (24% cheaper) but both produce quality content
            

The Verdict: Which is Cheaper?

After analyzing 10,000 requests across 8 task types:

Task Type	Cheaper Model	Cost Difference
Summarization	GPT-4o	12-18% cheaper
Simple Q&A	GPT-4o	15-22% cheaper
Code generation	GPT-4o	20-25% cheaper*
Long-form writing	GPT-4o	18-24% cheaper
Analysis/reasoning	Tie	Within 5%
Classification	Use mini models	Both overkill

* Despite being cheaper, Claude Sonnet has 8% higher first-run code success rate

Bottom line: For pure cost optimization, GPT-4o wins most tasks by 15-25%. However, for code generation, Claude Sonnet's higher quality may justify the 20-25% premium.

When to Use Each Model

Use GPT-4o When:

Cost is priority #1: You need to minimize spending
Summarization: GPT-4o handles this 15% cheaper with equal quality
Customer support: Fast responses, lower cost
Content generation: GPT-4o produces quality content 20% cheaper

Use Claude Sonnet When:

Code generation: 8% higher success rate justifies 25% higher cost
Complex reasoning: Claude excels at multi-step logic
Long context: Claude handles 200K tokens vs GPT-4o's 128K
Nuanced writing: Claude's style is more thoughtful/verbose

The Mini Models: Real Cost Winners

For 70% of tasks, neither GPT-4o nor Claude Sonnet is optimal. Use the mini models:

GPT-4o-mini: $0.15/1M input tokens

Perfect for: Classification, extraction, simple Q&A, sentiment analysis

Claude Haiku: $0.25/1M input tokens

Perfect for: Fast responses, simple summaries, FAQ answering

Cost comparison: Using GPT-4o-mini instead of GPT-4o for classification saves 94%—far more than the 15-25% saved by choosing GPT-4o over Claude.

Recommendation: Use Both

The optimal strategy isn't "OpenAI vs Anthropic"—it's intelligent routing across both:

Routing Strategy:
  - Classification/Extraction → GPT-4o-mini (cheapest)
  - Summarization → GPT-4o (15% cheaper than Claude)
  - Code generation → Claude Sonnet (higher quality)
  - Content writing → GPT-4o (20% cheaper, same quality)
  - Complex reasoning → Claude Sonnet (better at logic)
            

With intelligent routing, you get:

Lowest cost for each task type
Best quality for each use case
Automatic failover (if OpenAI is down, route to Claude)

Multi-Provider Routing with AI Gateway

AI Gateway routes intelligently between OpenAI and Anthropic. Get the best price/quality for every request automatically.

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