Claude Opus 4.8 (Fast) vs Grok 4.20
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 4.20: side by side
| Spec | Claude Opus 4.8 (Fast) | Grok 4.20 | Winner |
|---|---|---|---|
| Intelligence | 61.4 | 49.3 | Claude Opus 4.8 (Fast) |
| Output speed | 60 t/s | 161 t/s | Grok 4.20 |
| Output price | $50.00/1M | $2.50/1M | Grok 4.20 |
| Context | 1000K | 2000K | Grok 4.20 |
| 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 4.20
Pros
- +Handles extremely large contexts up to 2M tokens
- +Native support for text, image, and file inputs
- +Multimodal integration in a single model
Cons
- –No audio or video modality support
- –Very large context can increase latency
- –Performance depends on input quality and structure
Frequently asked questions
It depends on your needs. Claude Opus 4.8 (Fast) and Grok 4.20 are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.