Google Gemini 3.1 Flash-Lite Review — Budget Tier, Frontier Benchmarks, 62% Smarter Than 2.5 Flash

Gemini 3.1 Flash-Lite launched March 3, 2026 and reached GA in May 2026. It costs $0.25/$1.50 per million tokens, scores 34 on the Intelligence Index (62% above its predecessor), hits 86.9% on GPQA Diamond, and delivers 381 tokens per second — 45% faster than Gemini 2.5 Flash. We review benchmarks, the thinking_level system, multimodal capabilities, pricing, and where it fits against Flash and Pro.