xAI's Opus-class flagship for frontier coding, agentic tool use, and knowledge work.
Microsoft's compact research model with strong STEM reasoning.
No shared demos for these models yet.
No captured outputs for these models yet.
Based on the Capability Index, Grok 4.5 scores higher (88.5 vs 64.6). However, "better" depends on your use case — pricing, speed, context window, and specific capability needs all matter.
Phi 4 has a lower blended cost. Grok 4.5: $2.00 input / $6.00 output. Phi 4: $0.07 input / $0.14 output.
Grok 4.5 has a larger context window: Grok 4.5 supports 500K tokens vs Phi 4 at 16K tokens.
Grok 4.5 supports vision/image input, but Phi 4 does not.
Key differences: Grok 4.5 has a notably higher capability index (23.9 point gap); Phi 4 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 Phi 4 for free on idapt.app to see which performs better for your specific needs.