Gemini 3.5 Flash vs GPT-5.6 Luna
Price, context window & benchmark comparison
VS
Compare different models
Verdict: GPT-5.6 Luna is 7.5× cheaper than Gemini 3.5 Flash on a typical 3:1 input/output mix. GPT-5.6 Luna scores higher on the Artificial Analysis Intelligence Index (37.3 vs 32.6). GPT-5.6 Luna has the larger context window (1.1M vs 1M).
| Gemini 3.5 Flash | GPT-5.6 Luna | |
|---|---|---|
| Input price / 1M | $1.50 | $0.20 |
| Output price / 1M | $9.00 | $1.20 |
| Blended price (3:1) | $3.38 | $0.45 |
| Cached input / 1M | $0.15 | $0.02 |
| Context window | 1M | 1.1M |
| Max output | 66K | 128K |
| Intelligence index | 32.6 | 37.3 |
| Coding index | 70.1 | 71.4 |
| Providers | — | 7 |
| Best provider uptime (30m) | — | 100.0% |
| Vision input | Yes | Yes |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| Released | 2026-05-19 | 2026-07-09 |
| Retirement | — | — |
Cost calculator
FAQ
Which is cheaper, Gemini 3.5 Flash or GPT-5.6 Luna?
GPT-5.6 Luna is 7.5× cheaper than Gemini 3.5 Flash on a typical 3:1 input/output mix.
Gemini 3.5 Flash vs GPT-5.6 Luna: which has a bigger context window?
Gemini 3.5 Flash: 1,048,576 tokens. GPT-5.6 Luna: 1,050,000 tokens.
How much would 1 million requests cost?
At 2,000 input + 500 output tokens per request: Gemini 3.5 Flash ≈ $7,500, GPT-5.6 Luna ≈ $1,000.
More comparisons
Gemini 3.5 Flash vs GLM 5.3 PrimeGemini 3.5 Flash vs Qwen3.8 Max PrimeGemini 3.5 Flash vs Command A+Gemini 3.5 Flash vs GPT-6 Luna ProGemini 3.5 Flash vs GPT-6 LunaGemini 3.5 Flash vs GPT-6 Sol ProGemini 3.5 Flash vs GPT-6 SolGemini 3.5 Flash vs Claude Opus 5.5Gemini 3.5 Flash vs MiMo-V2.6-Pro-UltraSpeedGemini 3.5 Flash vs MiMo-V2.6-FlashGemini 3.5 Flash vs Grok 4.7Gemini 3.5 Flash vs Qwen3.8 Omni FlashGemini 3.5 Flash vs GLM 5.3 FlashXGemini 3.5 Flash vs DeepSeek V4.1 FlashGemini 3.5 Flash vs GPT-6 AstraGemini 3.5 Flash vs GPT-6 Astra ProGPT-5.6 Luna vs GLM 5.3 PrimeGPT-5.6 Luna vs Qwen3.8 Max PrimeGPT-5.6 Luna vs Command A+GPT-5.6 Luna vs GPT-6 Luna ProGPT-5.6 Luna vs GPT-6 LunaGPT-5.6 Luna vs GPT-6 Sol ProGPT-5.6 Luna vs GPT-6 SolGPT-5.6 Luna vs Claude Opus 5.5