AiCostCompare

Gemini 3.6 Flash vs GPT-5.6 Luna Pro (batch)

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

Prices updated Sep 17, 2026, 1:13 PM UTC · refreshed hourly

Gemini 3.6 Flash

Google

GPT-5.6 Luna Pro (batch)

OpenAI

Pricing
Input $/1M$0.75$0.10
Output $/1M$3.75$0.60
Blended $/1M (3:1)$1.50$0.225
RAG example (30K in / 2K out)$0.03$0.0042
Quality & speed
Intelligence Index34.3
Coding Index69.2
Agentic Index30.2
Output speed (tok/s)187
Time to first token13.49s
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 Pro (batch)?

GPT-5.6 Luna Pro (batch) has the lower blended API price at $0.225 per 1M tokens (3:1 input:output mix), versus $1.50 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 Pro (batch) costs about $0.0042 per request versus $0.03. Also compare context windows: Gemini 3.6 Flash offers 1.05M and GPT-5.6 Luna Pro (batch) offers 1.05M.

Which scores higher on Artificial Analysis benchmarks?

Gemini 3.6 Flash leads on the Artificial Analysis Intelligence Index (34.3 vs —). Check coding and agentic indices on this page for workload-specific tradeoffs.