Claude 3 Sonnet vs OpenAI o3
Performance benchmarks + pricing comparison — updated April 2026
Claude 3 Sonnet
AnthropicFirst generation Sonnet. Balanced performance for general tasks.
| Input | $3.00/M |
| Output | $15.00/M |
| Context | 200K tokens |
| Best For | General-purpose coding and reasoning |
| Benchmark | 65/100 |
OpenAI o3
OpenAINext generation reasoning model. Improved coding and math over o1.
| Input | $10.00/M |
| Output | $40.00/M |
| Context | 200K tokens |
| Best For | Advanced coding, complex problem-solving |
| Benchmark | 85/100 |
Benchmark Performance Comparison
Third-party benchmark scores — higher is better. Data sourced from SWE-bench, LiveCodeBench, HumanEval, and BigCodeBench.
| Benchmark | Claude 3 Sonnet | OpenAI o3 | Leader |
|---|---|---|---|
| Overall Score | 65 | 85 | o3 leads by 20pts |
| SWE-bench Verified | 58 | 82 | o3 leads by 24pts |
| LiveCodeBench | 68 | 88 | o3 leads by 20pts |
| HumanEval | 85 | 96 | o3 leads by 11pts |
| BigCodeBench | 50 | 74 | o3 leads by 24pts |
Cost Comparison by Scenario
Estimated cost per project with 30% cache hit rate. Actual costs may vary based on usage patterns.
| Scenario | Claude 3 Sonnet | OpenAI o3 | Savings |
|---|---|---|---|
| Small Script (1K lines) | $0.55 | $1.55 | Claude 3 Sonnet saves $1.00 (64%) |
| Medium Feature (10K lines) | $4.05 | $11.50 | Claude 3 Sonnet saves $7.45 (65%) |
| Large Project (50K lines) | $20.25 | $57.50 | Claude 3 Sonnet saves $37.25 (65%) |
| Code Review (5K lines) | $0.90 | $2.75 | Claude 3 Sonnet saves $1.85 (67%) |
Value Analysis (Price per Benchmark Score Point)
Lower is better — how much you pay for each point of benchmark performance.
| Model | Overall Score | Price per Score Point | Verdict |
|---|---|---|---|
| Claude 3 Sonnet | 65 | $0.046/pt | Better value |
| OpenAI o3 | 85 | $0.167/pt | Higher cost per point |
Claude 3 Sonnet delivers the best value at $0.046 per score point.
Strengths & Weaknesses
Claude 3 Sonnet
- + Reliable
- + Good value
- - Two generations behind
OpenAI o3
- + Latest reasoning model
- + Top-tier across all benchmarks
- - Very expensive
- - Slow
Verdict
Claude 3 Sonnet is cheaper at $3.00/M, but OpenAI o3 scores higher on benchmarks (85 vs 65).
Choose Claude 3 Sonnet for cost-sensitive projects, OpenAI o3 when performance matters most.
Compare with Other Models
Claude Sonnet 4
AnthropicAnthropic's balanced model for coding and general tasks. Best price-performance ratio in the Claude family.
Claude Opus 4
AnthropicAnthropic's most powerful model. Best for complex reasoning and challenging coding tasks.
Claude 3.5 Sonnet
AnthropicPrevious generation Sonnet. Still excellent for coding tasks at the same price point.
Claude 3.5 Haiku
AnthropicFast, cost-effective model for high-volume tasks. Great for code review and simple queries.
Claude 3 Opus
AnthropicFirst generation Opus. Highest reasoning capability in the Claude 3 family.
Claude 3 Haiku
AnthropicCheapest Claude model. Fast responses for simple tasks and basic coding.