Side-by-side comparison of AI model specs, benchmarks, and pricing.
| Spec | Claude Sonnet 4.5 Anthropic | GPT-5.3 Codex OpenAI |
|---|---|---|
| Tier | frontier | frontier |
| Release Date | 2025-09-29 | 2026-02-05 |
| Context Window | 200K | 400K |
| Max Output | 64K | 128K |
| Input Price (/1M) | $3 | $1.75 |
| Output Price (/1M) | $15 | $14 |
| Arena Elo | 1,450 | 1,480 |
| MMLU | 88.7% | 93% |
| GPQA | 83.4% | 81% |
| MATH | 87% | 96% |
| HumanEval | 95% | 93% |
| SWE-bench | 55.8% | 80% |
| AIME | 58% | 94% |
| SimpleQA | 30.8% | 58% |
| Capabilities | vision, tool-use, code, extended-thinking | vision, tool-use, code, reasoning, agentic |