Updated March 26, 2026· Based on independent benchmark data
GPT-5.3 Codex (xhigh) leads in intelligence with a score of 54.0 vs 43.0. GPT-5.3 Codex (xhigh) is 1.7x cheaper at $1.75/1M tokens vs $3.00/1M. For speed, GPT-5.3 Codex (xhigh) wins at 72 tok/s vs 52 tok/s.
| Metric | Claude 4.5 Sonnet (Reasoning) | GPT-5.3 Codex (xhigh) |
|---|---|---|
| Intelligence Score | 43.0 | 54.0 |
| Coding Score | 38.6 | 53.1 |
| Math Score | 88.0 | N/A |
| Speed (tok/s) | 52 tok/s | 72 tok/s |
| Latency (TTFT) | 7.94s | 83.91s |
| Input Price / 1M tokens | $3.00 | $1.75 |
| Output Price / 1M tokens | $15 | $14 |
| Context Window | N/A |
GPT-5.3 Codex (xhigh) outperforms Claude 4.5 Sonnet (Reasoning) on the intelligence index with a score of 54.0 compared to 43.0. For coding tasks, GPT-5.3 Codex (xhigh) has the edge with a coding score of 53.1 vs 38.6.
GPT-5.3 Codex (xhigh) generates output significantly faster at 72 tok/s compared to Claude 4.5 Sonnet (Reasoning)'s 52 tok/s, making it 1.4x faster for streaming responses. Time to first token is 7.94s for Claude 4.5 Sonnet (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 4.5 Sonnet (Reasoning) costs $3.00/1M input ($15/1M output). For a typical workload of 100 requests per day at 2,000 tokens each, Claude 4.5 Sonnet (Reasoning) would cost approximately $18.00/month vs $10.50/month for GPT-5.3 Codex (xhigh) in input costs alone.
Choose GPT-5.3 Codex (xhigh) when you need higher intelligence (54.0), stronger coding performance (53.1), faster output (72 tok/s), lower cost.
GPT-5.3 Codex (xhigh) scores higher on coding benchmarks (53.1 vs 38.6), making it the better choice for programming tasks.
GPT-5.3 Codex (xhigh) is cheaper at $1.75/1M input tokens vs $3.00/1M for Claude 4.5 Sonnet (Reasoning).
GPT-5.3 Codex (xhigh) is faster, producing output at 72 tok/s compared to Claude 4.5 Sonnet (Reasoning)'s 52 tok/s.
No, Claude 4.5 Sonnet (Reasoning) 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 4.5 Sonnet (Reasoning) may be better for specific use cases like budget-conscious projects or speed-critical applications.