Quick Take

This comparison evaluates Google's Gemini 3.5 Flash (minimal) and OpenAI's GPT-5.5 (xhigh). Released in April and May 2026 respectively, these models represent different strategic priorities: Gemini 3.5 Flash focuses on high-speed, cost-effective execution, whereas GPT-5.5 is engineered for peak intelligence and analytical capability.

Benchmark Read

GPT-5.5 consistently outperforms Gemini 3.5 Flash across all provided metrics.

• Intelligence & Coding: GPT-5.5 leads with an intelligence index of 60.2 and a coding index of 59.1, compared to Gemini's 43.3 and 47.1.
• Reasoning Benchmarks: GPT-5.5 demonstrates higher proficiency in complex tasks, scoring 0.935 on GPQA and 0.938 on TAU2, significantly ahead of Gemini's 0.828 and 0.587 respectively.
• Instruction Following: GPT-5.5 achieves an IFBench score of 0.758, notably higher than Gemini's 0.472.

Cost and Speed

There is a stark contrast in operational performance:

• Pricing: Gemini 3.5 Flash is significantly more affordable, with a blended cost of $3.38/1M tokens, compared to $11.25/1M for GPT-5.5.
• Speed: Gemini 3.5 Flash delivers an output speed of 225.728 tok/s with a time to first token of 0.891s. In contrast, GPT-5.5 operates at 65.375 tok/s with a substantial 71.023s time to first token, making it less suitable for real-time, low-latency requirements.

Best Fit

Gemini 3.5 Flash is the optimal choice for developers building high-throughput applications where latency is critical and budget is a primary concern. GPT-5.5 is best suited for enterprise-grade research, complex coding projects, and tasks where the highest possible reasoning accuracy is required, regardless of the higher latency and cost.