Claude Opus 4.8 (Fast) vs Grok 4.3
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 Grok 4.3: side by side
| Spec | Claude Opus 4.8 (Fast) | Grok 4.3 | Winner |
|---|---|---|---|
| Intelligence | 61.4 | 43.9 | Claude Opus 4.8 (Fast) |
| Output speed | 62 t/s | 135 t/s | Grok 4.3 |
| Output price | $50.00/1M | $2.50/1M | Grok 4.3 |
| Context | 1000K | 1000K | Tie |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | xAI | 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
Grok 4.3
Pros
- +Strong performance on complex multi-step reasoning
- +Large context window for document-level tasks
- +Helpful and direct response style
- +Integrated real-time tool access
Cons
- –Vision capabilities less mature than specialized models
- –Occasional over-refusal on edge-case queries
- –High computational cost for maximum context usage
Frequently asked questions
It depends on your needs. Claude Opus 4.8 (Fast) and Grok 4.3 are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.