Grok 4.6 vs Gemini 3.8 Flash

Grok 4.6 (xAI) and Gemini 3.8 Flash (Google) compared on price, context window, speed and independent benchmarks. Grok 4.6 scores higher on the Artificial Analysis Intelligence Index (60.9 vs 58.7), while Gemini 3.8 Flash is 2.0× cheaper on a blended basis. Pick Grok 4.6 for the hardest tasks and Gemini 3.8 Flash when cost dominates.

Grok 4.6Gemini 3.8 Flash
ProviderxAIGoogle
Input $/1M$2.00$0.75
Output $/1M$6.00$3.75
Blended $/1M (3:1)$3.00$1.50
Cached input $/1M$0.50$0.07
Context window500K1.0M
Knowledge cutoff2026-02
Licenseproprietaryproprietary
Speed (tok/s)60417
Artificial Analysis Intelligence Index60.958.7
LMArena Elo1444
GPQA Diamond94.9%95.3%
Humanity's Last Exam42.9%47.8%

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