Updated March 26, 2026· Based on independent benchmark data
GPT-5.3 Codex (xhigh) leads in intelligence with a score of 54.0 vs 49.7. GPT-5.3 Codex (xhigh) is 2.9x cheaper at $1.75/1M tokens vs $5.00/1M.
| Metric | GPT-5.3 Codex (xhigh) | Claude Opus 4.5 (Reasoning) |
|---|---|---|
| Intelligence Score | 54.0 | 49.7 |
| Coding Score | 53.1 | 47.8 |
| Math Score | N/A | 91.3 |
| Speed (tok/s) | 72 tok/s | 57 tok/s |
| Latency (TTFT) | 83.91s | 10.41s |
| Input Price / 1M tokens | $1.75 | $5.00 |
| Output Price / 1M tokens | $14 | $25 |
| Context Window | N/A |
GPT-5.3 Codex (xhigh) outperforms Claude Opus 4.5 (Reasoning) on the intelligence index with a score of 54.0 compared to 49.7. For coding tasks, GPT-5.3 Codex (xhigh) has the edge with a coding score of 53.1 vs 47.8.
GPT-5.3 Codex (xhigh) generates output significantly faster at 72 tok/s compared to Claude Opus 4.5 (Reasoning)'s 57 tok/s, making it 1.3x faster for streaming responses. Time to first token is 10.41s for Claude Opus 4.5 (Reasoning) vs 83.91s for GPT-5.3 Codex (xhigh), which affects perceived responsiveness in interactive applications.
GPT-5.3 Codex (xhigh) is more affordable at $1.75/1M input tokens ($14/1M output), while Claude Opus 4.5 (Reasoning) costs $5.00/1M input ($25/1M output). That makes Claude Opus 4.5 (Reasoning) 2.9x 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, GPT-5.3 Codex (xhigh) would cost approximately $10.50/month vs $30.00/month for Claude Opus 4.5 (Reasoning) in input costs alone.
Choose GPT-5.3 Codex (xhigh) when you need higher intelligence (54.0), stronger coding performance (53.1), lower cost.
GPT-5.3 Codex (xhigh) scores higher on coding benchmarks (53.1 vs 47.8), making it the better choice for programming tasks.
GPT-5.3 Codex (xhigh) is cheaper at $1.75/1M input tokens vs $5.00/1M for Claude Opus 4.5 (Reasoning).
GPT-5.3 Codex (xhigh) is faster, producing output at 72 tok/s compared to Claude Opus 4.5 (Reasoning)'s 57 tok/s.
No, GPT-5.3 Codex (xhigh) does not support image input. Neither model supports image input.
Data last synced: March 26, 2026
| 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. GPT-5.3 Codex (xhigh) scores higher on intelligence (54.0), but Claude Opus 4.5 (Reasoning) may be better for specific use cases like budget-conscious projects or speed-critical applications.