Claude Opus 4.8 (Fast) vs GPT-5.5 Pro
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 4.8 (Fast) vs GPT-5.5 Pro: side by side
| Spec | Claude Opus 4.8 (Fast) | GPT-5.5 Pro | Winner |
|---|---|---|---|
| Intelligence | 55.7 | — | Tie |
| Output speed | 62 t/s | — | Tie |
| Output price | $50.00/1M | $180.00/1M | Claude Opus 4.8 (Fast) |
| Context | 1000K | 1050K | GPT-5.5 Pro |
| Params | — | — | Tie |
| Provider | Anthropic | OpenAI | Tie |
Claude Opus 4.8 (Fast)
Pros
- +Strong safety alignment
- +Nuanced and careful reasoning
- +Effective large-context handling
Cons
- –Can be overly cautious on edge cases
- –Multimodal performance varies with image clarity
- –Fast mode may trade some depth for speed
GPT-5.5 Pro
Pros
- +Very large context window
- +Native support for files, images, and text
- +Seamless multimodal integration
Cons
- –High resource use with maximum context
- –No audio or video modalities
- –Potential latency on very long inputs
Frequently asked questions
It depends on your needs. Claude Opus 4.8 (Fast) and GPT-5.5 Pro are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.