Gemini 3.5 Flash Review: Features, Benchmarks, Pricing and more

Google released Gemini 3.5 Flash on May 19, 2026, at I/O, positioning it as a high-intelligence, speed-optimized model for sustained frontier performance in agentic workflows, coding, and multimodal tasks. It builds on the Gemini 3 Flash foundation with enhanced "thinking levels" for balancing quality, cost, and latency. This comprehensive guide covers everything: what Gemini 3.5 Flash is, its key features, detailed benchmark performance, pricing, comparisons to GPT-5.5, Claude 4.7/4.6, and more.