Google Gemini 3.5 Flash VS OpenAI GPT-5.6 Luna
Decision Recommendation
👑 Editorial Verdict: GPT-5.6 Luna strictly dominates Gemini 3.5 Flash across all compared dimensions. It is not only more cost-effective (blended cost of $2.25 vs $3.38 per 1M tokens) but also delivers superior coding accuracy (62.7% vs 55.1% on SWE-bench). Unless you have platform lock-in, GPT-5.6 Luna is the clear and optimal choice for all development workloads.
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Model Specs
Gemini 3.5 Flash
Benchmarks & Scores
Coding (swe-bench-pro)
55.1%excellent at multi-file repositories, autonomous agents, and industrial codebases
Reasoning (gpqa-diamond)
92.2%graduate-level science QA
Cost & Performance
Cost (per 1M tokens)
$3.38Input: $1.50 | Output: $9.00Context Window
1M tokensModel Specs
GPT-5.6 Luna
Benchmarks & Scores
Coding (swe-bench-pro)Winner (+7.6%)
62.7%excellent at multi-file repositories, autonomous agents, and industrial codebases
Reasoning (gpqa-diamond)Winner (+0.1%)
92.3%graduate-level science QA
Cost & Performance
Cost (per 1M tokens)1.5x cheaper
$2.25Input: $1.00 | Output: $6.00Context WindowLarger
1.05M tokensFrequently Asked Questions about Gemini 3.5 Flash vs GPT-5.6 Luna comparison
GPT-5.6 Luna is cheaper than Gemini 3.5 Flash. GPT-5.6 Luna has a blended cost of $2.25/1M tokens, which is about 1.5x cheaper than Gemini 3.5 Flash at $3.38/1M tokens.
GPT-5.6 Luna is better for coding tasks on this benchmark. It scores 62.7% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) compared to Gemini 3.5 Flash which scores 55.1%.
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