Claude Opus 4.6 (Fast) vs GPT-5.1-Codex
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Claude Opus 4.6 (Fast) vs GPT-5.1-Codex: side by side
| Spec | Claude Opus 4.6 (Fast) | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Intelligence | 52.9 | 43.1 | Claude Opus 4.6 (Fast) |
| Output speed | 40 t/s | 178 t/s | GPT-5.1-Codex |
| Output price | $150.00/1M | $10.00/1M | GPT-5.1-Codex |
| Context | 1000K | 400K | Claude Opus 4.6 (Fast) |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | OpenAI | Tie |
Claude Opus 4.6 (Fast)
Pros
- +Strong reasoning depth
- +Effective large-context handling
- +Safety-conscious responses
- +Fast inference for its class
Cons
- –May refuse borderline requests
- –Conservative output style
- –Vision limited to static images
GPT-5.1-Codex
Pros
- +Strong performance on extended coding workflows
- +Effective integration of visual context with code
- +Handles very large inputs without losing coherence
- +Specialized for software development tasks
Cons
- –Limited to text and image inputs only
- –High computational cost for maximum context
- –May require careful prompt engineering for complex tasks
Frequently asked questions
It depends on your needs. Claude Opus 4.6 (Fast) and GPT-5.1-Codex are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.