xAI's Opus-class flagship for frontier coding, agentic tool use, and knowledge work.
September 2025 checkpoint of Kimi K2 with improved capabilities.
No shared demos for these models yet.
No captured outputs for these models yet.
Both Grok 4.5 and Kimi K2 (0905) are capable AI models. The best choice depends on your specific use case: consider pricing, context window, speed, and which capabilities (vision, reasoning, audio) you need.
Kimi K2 (0905) has a lower blended cost. Grok 4.5: $2.00 input / $6.00 output. Kimi K2 (0905): $0.60 input / $2.50 output.
Grok 4.5 has a larger context window: Grok 4.5 supports 500K tokens vs Kimi K2 (0905) at 262K tokens.
Grok 4.5 supports vision/image input, but Kimi K2 (0905) does not.
Key differences: Kimi K2 (0905) is significantly cheaper; only Grok 4.5 supports vision input; only Grok 4.5 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 4.5 and Kimi K2 (0905) for free on idapt.app to see which performs better for your specific needs.