AiCostCompare

Gemini 3.6 Flash vs GPT-5.6 Luna

Side-by-side API pricing and Artificial Analysis performance for Gemini 3.6 Flash (Google) and GPT-5.6 Luna (OpenAI). Green cells mark the better value in each row.

Prices updated Jul 22, 2026, 1:39 AM UTC · refreshed hourly

Gemini 3.6 Flash

Google

GPT-5.6 Luna

OpenAI

Pricing
Input $/1M$1.50$1.00
Output $/1M$7.50$6.00
Blended $/1M (3:1)$3.00$2.25
RAG example (30K in / 2K out)$0.06$0.042
Quality & speed
Intelligence Index50.151.2
Coding Index69.271.4
Agentic Index38.745.6
Output speed (tok/s)301203
Time to first token11.80s102.47s
Specs
Context window1.05M1.05M
Input modalitiestext, image, video, file, audiofile, image, text

FAQ

Which is cheaper, Gemini 3.6 Flash or GPT-5.6 Luna?

GPT-5.6 Luna has the lower blended API price at $2.25 per 1M tokens (3:1 input:output mix), versus $3.00 for the other model. Prices are live from OpenRouter and refresh about hourly.

Which is better for RAG workloads?

For a typical RAG request (30K input / 2K output tokens), GPT-5.6 Luna costs about $0.042 per request versus $0.06. Also compare context windows: Gemini 3.6 Flash offers 1.05M and GPT-5.6 Luna offers 1.05M.

Which scores higher on Artificial Analysis benchmarks?

GPT-5.6 Luna leads on the Artificial Analysis Intelligence Index (51.2 vs 50.1). Check coding and agentic indices on this page for workload-specific tradeoffs.