OpenAI's fastest, most affordable GPT-5.6 tier for high-volume, latency-sensitive work.
Microsoft's compact research model with strong STEM reasoning.
No shared demos for these models yet.
No captured outputs for these models yet.
Both GPT 5.6 Luna and Phi 4 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.
Phi 4 has a lower blended cost. GPT 5.6 Luna: $1.00 input / $6.00 output. Phi 4: $0.07 input / $0.14 output.
GPT 5.6 Luna has a larger context window: GPT 5.6 Luna supports 1.1M tokens vs Phi 4 at 16K tokens.
GPT 5.6 Luna supports vision/image input, but Phi 4 does not.
Key differences: Phi 4 is significantly cheaper; only GPT 5.6 Luna supports vision input; only GPT 5.6 Luna 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 GPT 5.6 Luna and Phi 4 for free on idapt.app to see which performs better for your specific needs.