Updated March 26, 2026· Based on independent benchmark data
Claude Opus 4.5 (Reasoning) leads in intelligence with a score of 49.7 vs 44.6. GPT-5 Codex (high) is 4.0x cheaper at $1.25/1M tokens vs $5.00/1M. For speed, GPT-5 Codex (high) wins at 180 tok/s vs 57 tok/s.
| Metric | Claude Opus 4.5 (Reasoning) | GPT-5 Codex (high) |
|---|---|---|
| Intelligence Score | 49.7 | 44.6 |
| Coding Score | 47.8 | 38.9 |
| Math Score | 91.3 | 98.7 |
| Speed (tok/s) | 57 tok/s | 180 tok/s |
| Latency (TTFT) | 10.41s | 9.17s |
| Input Price / 1M tokens | $5.00 | $1.25 |
| Output Price / 1M tokens | $25 | $10 |
| Context Window |
Claude Opus 4.5 (Reasoning) outperforms GPT-5 Codex (high) on the intelligence index with a score of 49.7 compared to 44.6. For coding tasks, Claude Opus 4.5 (Reasoning) has the edge with a coding score of 47.8 vs 38.9. In mathematical reasoning, GPT-5 Codex (high) leads with 98.7 compared to Claude Opus 4.5 (Reasoning)'s 91.3.
GPT-5 Codex (high) generates output significantly faster at 180 tok/s compared to Claude Opus 4.5 (Reasoning)'s 57 tok/s, making it 3.2x faster for streaming responses. Time to first token is 9.17s for GPT-5 Codex (high) vs 10.41s for Claude Opus 4.5 (Reasoning), which affects perceived responsiveness in interactive applications.
GPT-5 Codex (high) is more affordable at $1.25/1M input tokens ($10/1M output), while Claude Opus 4.5 (Reasoning) costs $5.00/1M input ($25/1M output). That makes Claude Opus 4.5 (Reasoning) 4.0x more expensive per token, which can add up significantly at scale. For a typical workload of 100 requests per day at 2,000 tokens each, Claude Opus 4.5 (Reasoning) would cost approximately $30.00/month vs $7.50/month for GPT-5 Codex (high) in input costs alone.
Choose Claude Opus 4.5 (Reasoning) when you need higher intelligence (49.7), stronger coding performance (47.8). Choose GPT-5 Codex (high) when you need faster output (180 tok/s), lower cost.
Claude Opus 4.5 (Reasoning) scores higher on coding benchmarks (47.8 vs 38.9), making it the better choice for programming tasks.
GPT-5 Codex (high) is cheaper at $1.25/1M input tokens vs $5.00/1M for Claude Opus 4.5 (Reasoning).
GPT-5 Codex (high) is faster, producing output at 180 tok/s compared to Claude Opus 4.5 (Reasoning)'s 57 tok/s.
No, Claude Opus 4.5 (Reasoning) does not support image input. Neither model supports image input.
Data last synced: March 26, 2026
| N/A |
| N/A |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Text |
| Output Modalities | Text | Text |
| Free Tier | No | No |
It depends on your priorities. Claude Opus 4.5 (Reasoning) scores higher on intelligence (49.7), but GPT-5 Codex (high) may be better for specific use cases like budget-conscious projects or speed-critical applications.