OpenAI o1 vs Claude 4: Which Model for Complex Reasoning?
OpenAI’s o1 (Strawberry) and Claude 4 take different approaches to reasoning. We tested both on complex engineering problems to see which delivers better results.
How They Work
- o1 — Uses internal chain-of-thought reasoning, “thinking” before responding
- Claude 4 — Direct response with extensive context window
Test Results
Task 1: Debug Distributed System Issue
Prompt: Three services are logging connection timeouts to Redis. Services A, B, C all fail independently. Debug.
| Model | Score | Root Cause | Solution |
|---|---|---|---|
| o1 | 9.3 | ✓ Identified network partition | Comprehensive |
| Claude 4 | 9.1 | ✓ Identified connection pool | Good |
Task 2: Design Event Sourcing System
Prompt: Design an event sourcing architecture for an e-commerce order system.
| Model | Score | Completeness | Practicality |
|---|---|---|---|
| o1 | 9.0 | Good | Good |
| Claude 4 | 9.4 | Excellent | Excellent |
Claude 4 provided better schema design and migration strategy.
Task 3: Optimize Slow SQL Query
Prompt: This query takes 30 seconds. Optimize it.
| Model | Score | Optimization | Indexes |
|---|---|---|---|
| o1 | 8.9 | Good | Missing 1 |
| Claude 4 | 9.2 | Excellent | Complete |
Speed
| Model | Time (avg) | Think Time |
|---|---|---|
| o1 | 12s | 8s |
| Claude 4 | 4s | 0s |
o1 is significantly slower due to reasoning.
Cost
| Model | Price |
|---|---|
| o1 | $15.00/1M |
| Claude 4 | $15.00/1M |
Same price tier.
When to Use What
- Use o1 for: Math, science, complex logic
- Use Claude 4: Coding, writing, general reasoning
Both are excellent. Claude 4 is faster and better for coding.