Claude Opus 4.8 (Fast) vs Claude Sonnet 4.5
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 Claude Sonnet 4.5: side by side
| Spec | Claude Opus 4.8 (Fast) | Claude Sonnet 4.5 | Winner |
|---|---|---|---|
| Intelligence | 61.4 | — | Tie |
| Output speed | 60 t/s | — | Tie |
| Output price | $50.00/1M | $15.00/1M | Claude Sonnet 4.5 |
| Context | 1000K | 1000K | Tie |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | Anthropic | Tie |
Claude Opus 4.8 (Fast)
Pros
- +Strong safety alignment
- +Nuanced and careful reasoning
- +Effective large-context handling
- +High-quality writing and analysis
Cons
- –Can be overly cautious on edge cases
- –Multimodal performance varies with image clarity
- –Fast mode may trade some depth for speed
Claude Sonnet 4.5
Pros
- +Strong safety alignment
- +Reliable handling of large contexts
- +Careful and detailed reasoning
- +Effective multimodal file support
Cons
- –Can be overly cautious with refusals
- –Vision performance varies by image complexity
- –May produce verbose responses
Frequently asked questions
It depends on your needs. Claude Opus 4.8 (Fast) and Claude Sonnet 4.5 are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.