OpenAI's previous frontier model for complex professional workloads, built on GPT-5.4 with stronger reasoning and higher reliability.
OpenAI's fastest, most affordable GPT-6 tier for high-volume, latency-sensitive work.
No shared demos for these models yet.
No captured outputs for these models yet.
Both GPT 5.5 and GPT 6 Luna 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.
GPT 6 Luna has a lower blended cost. GPT 5.5: $5.00 input / $30.00 output. GPT 6 Luna: $0.10 input / $0.50 output.
GPT 5.5 has a larger context window: GPT 5.5 supports 1.1M tokens vs GPT 6 Luna at 1.1M tokens.
Yes, both GPT 5.5 and GPT 6 Luna support vision/image input.
Key differences: GPT 6 Luna is significantly cheaper. 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 5.5 and GPT 6 Luna for free on idapt.app to see which performs better for your specific needs.