Fast version of Grok 4 with SOTA cost-efficiency and 2M-token context.
Anthropic's fifth-generation Sonnet — near-Opus intelligence at Sonnet speed and price.
No shared demos for these models yet.
No captured outputs for these models yet.
Based on the Capability Index, Claude Sonnet 5 scores higher (80.1 vs 77.0). However, "better" depends on your use case — pricing, speed, context window, and specific capability needs all matter.
Grok 4 Fast has a larger context window: Grok 4 Fast supports 2M tokens vs Claude Sonnet 5 at 1M tokens.
Yes, both Grok 4 Fast and Claude Sonnet 5 support vision/image input.
Key differences: only Claude Sonnet 5 offers extended reasoning mode. Compare full specs on this page.
If cost is your priority, choose the cheaper option. If you need the highest intelligence for complex tasks, pick the higher-scoring model. For long documents or codebases, choose the larger context window. You can try both Grok 4 Fast and Claude Sonnet 5 for free on idapt.app to see which performs better for your specific needs.