Gemini 3.8 Flash vs GPT-5.6 Luna.
GPT-5.6 Luna is 3.3x cheaper.
For a chatbot doing 100K requests a month with 1,000 input and 500 output tokens each: $80.00 vs $262.50.
Google Gemini
Gemini 3.8 Flash
| Input / 1M | $0.75 |
| Cached / 1M | $0.075 |
| Output / 1M | $3.75 |
| Context | — |
| Chatbot at 100K req/mo | $262.50 |
Source · Oct 20, 2026
OpenAI
GPT-5.6 Luna
| Input / 1M | $0.20 |
| Cached / 1M | $0.02 |
| Output / 1M | $1.20 |
| Context | — |
| Chatbot at 100K req/mo | $80.00 |
Source · Oct 20, 2026
Sponsored
Your API or dev tool here. Reach developers comparing model costs right now.Price isn't everything: check quality on your own prompts. GPT-5.6 Luna wins on list price for this workload, but output-heavy jobs (long answers, agents, reasoning) shift the math toward whichever model has the lower output price, which here is GPT-5.6 Luna.