Claude Opus vs GPT-5.1-Codex
Anthropic vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1-Codex is cheaper ($1.25 vs $5.00 per 1M input)
- •Claude Opus has a larger context window (1M)
| Claude Opus | GPT-5.1-Codex | |
|---|---|---|
| Intelligence index | — | 88.2 |
| Developer | Anthropic | OpenAI |
| Type | Multimodal | Multimodal |
| Access | API only | API only |
| Context window | 1,000,000 tokens | 400,000 tokens |
| Input price | $5.00 / 1M | $1.25 / 1M |
| Output price | $25.00 / 1M | $10.00 / 1M |
| Speed | — | 188 tok/s |
| Released | April 21, 2026 | November 13, 2025 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |