Gemini 3.6 Flash vs GPT-5.6 Luna: Specs & Benchmark Comparison
Gemini 3.6 Flash is developed by Google, while GPT-5.6 Luna comes from OpenAI. Both were released in July 2026.
The two models share 4 published benchmarks. GPT-5.6 Luna leads on 3 of them, Gemini 3.6 Flash on 1. The widest gaps are on DeepSWE 1.1, where GPT-5.6 Luna scores 67.0% against 49.0%; MRCR v2 (8-needle), where Gemini 3.6 Flash scores 54.0% against 41.3%. Averaged across everything we track, Gemini 3.6 Flash sits at 68.0% and GPT-5.6 Luna at 51.5%.
GPT-5.6 Luna is the cheaper API at $0.20 per million input tokens and $1.20 per million output tokens, roughly 8 times cheaper than Gemini 3.6 Flash at $1.50 and $7.50. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Gemini 3.6 Flash | GPT-5.6 Luna |
|---|---|---|
| Company | OpenAI | |
| Release Date | July 21, 2026 | July 9, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.1M |
| Context (output) | 66K | 128K |
| Input Price / 1M | $1.50 | $0.20 |
| Output Price / 1M | $7.50 | $1.20 |
| Average Score | 68.0% | 51.5% |
| Benchmarks | ||
| DeepSWE 1.1 | 49.0% | 67.0% |
| MRCR v2 (8-needle) | 54.0% | 41.3% |
| Terminal-Bench 2.1 | 78.0% | 84.7% |
| SWE-Bench Pro | 58.7% | 62.7% |
Visual Benchmark Comparison
Verdict
GPT-5.6 Luna leads in 2 out of 4 comparison categories.
Both models show comparable average scores: Gemini 3.6 Flash — 0.7, GPT-5.6 Luna — 0.5.
GPT-5.6 Luna is 6.4x cheaper: input $0.20/1M vs $1.50/1M tokens.
GPT-5.6 Luna supports a larger context: 1M vs 1M tokens.
Both models were released around the same time: 7/21/2026 and 7/9/2026.
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Frequently Asked Questions
Which is better for coding — Gemini 3.6 Flash or GPT-5.6 Luna?
Which model is cheaper — Gemini 3.6 Flash or GPT-5.6 Luna?
Which has a larger context window — Gemini 3.6 Flash or GPT-5.6 Luna?
The Gemini 3.6 Flash and GPT-5.6 Luna comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Gemini 3.6 Flash or GPT-5.6 Luna page. See also the complete list of AI model comparisons.