Which model is better: Gemini 3.1 Pro or Gemini 3.8 Flash?
Gemini 3.8 Flash is 80.0% cheaper for input tokens ($0.25 vs. $1.25 per 1M tokens) and $1.50 vs. $10.00 for output tokens (5.0x cost advantage). In terms of operational performance, Gemini 3.8 Flash delivers lower response latency at 105ms TTFT (315ms faster than Gemini 3.1 Pro) with 210 vs. 98 tok/s throughput. Gemini 3.1 Pro leads coding evaluations at 71.8% SWE-bench Verified vs. 68.5% for Gemini 3.8 Flash and 82.4% vs. 79.2% on GPQA Diamond.
Verified daily via automated API latency tests and official documentation.
Zero-Shot RAG Verified
Verified Performance & Unit Economics Delta (12 Dimensions)
Daily synchronized metrics across token pricing, prompt cache economics, latency, throughput, and 5 capability benchmarks.
Metric / Dimension
Gemini 3.1 Pro
Gemini 3.8 Flash
Net Delta / Advantage
Input Cost / 1M Tokens
$1.25
$0.25
Gemini 3.8 Flash is 5.0x cheaper
Output Cost / 1M Tokens
$10.00
$1.50
Gemini 3.8 Flash (85.0% lower)
Prompt Cache Read / 1M
$0.310
$0.025
Gemini 3.8 Flash is 12.4x cheaper
Prompt Cache Write / 1M
$1.25
$0.25
Gemini 3.8 Flash is 5.0x cheaper
Context Window (Max Output)
1,049k (66k out)
1,049k (66k out)
Equal Context Window
Avg TTFT Response Latency
420ms
105ms
Gemini 3.8 Flash (315ms faster)
Generation Speed (Throughput)
98 tok/s
210 tok/s
Gemini 3.8 Flash (+112 tok/s faster)
SWE-bench Verified (Coding)
71.8%
68.5%
Gemini 3.1 Pro (+3.3% lead)
GPQA Diamond (PhD STEM)
82.4%
79.2%
Gemini 3.1 Pro (+3.2% lead)
MMLU-Pro (Multi-Discipline)
89.5%
87.4%
Gemini 3.1 Pro (+2.1% lead)
MATH-500 (Quantitative Logic)
96.8%
95.1%
Gemini 3.1 Pro (+1.7% lead)
Inference Value Score (IVR)
60 / 100
74 / 100
Gemini 3.8 Flash (+14 pts)
Interactive Monthly Token Economics & ROI Forecaster
Model production workloads across prompt, completion, and cached context tokens, or switch models on the fly.
Choose Gemini 3.1 Pro (Google) for complex enterprise architecture planning, multi-file code refactoring, legal/financial corpus auditing, and multimodal research — offering a 1,048k context window, 420ms TTFT, and $1.25/1M input pricing ($0.310/1M cached reads).
Choose Gemini 3.8 Flash (Google) for high-throughput agentic workflows, real-time multimodal RAG, live search grounding, and production code generation at flash unit economics — offering a 1,048k context window, 105ms TTFT, and $0.25/1M input pricing ($0.025/1M cached reads).
Which is cheaper: Gemini 3.1 Pro or Gemini 3.8 Flash?
Gemini 3.8 Flash is cheaper at $0.25/1M input tokens ($1.50/1M output) compared to $1.25/1M input ($10.00/1M output) for Gemini 3.1 Pro.
Which model has lower TTFT latency and higher tok/s throughput: Gemini 3.1 Pro or Gemini 3.8 Flash?
Gemini 3.8 Flash delivers faster first-token latency at 105ms TTFT (210 tok/s throughput) compared to 420ms TTFT (98 tok/s) for Gemini 3.1 Pro.
How do Gemini 3.1 Pro and Gemini 3.8 Flash compare on SWE-bench coding and GPQA Diamond reasoning?
On SWE-bench Verified software engineering, Gemini 3.1 Pro scores 71.8% versus 68.5% for Gemini 3.8 Flash. On GPQA Diamond graduate-level STEM reasoning, Gemini 3.1 Pro scores 82.4% versus 79.2% for Gemini 3.8 Flash (and 96.8% vs 95.1% on MATH-500).
When should you choose Gemini 3.1 Pro?
Choose Gemini 3.1 Pro (Google) for complex enterprise architecture planning, multi-file code refactoring, legal/financial corpus auditing, and multimodal research — offering a 1,048k context window, 420ms TTFT, and $1.25/1M input pricing ($0.310/1M cached reads).
When should you choose Gemini 3.8 Flash?
Choose Gemini 3.8 Flash (Google) for high-throughput agentic workflows, real-time multimodal RAG, live search grounding, and production code generation at flash unit economics — offering a 1,048k context window, 105ms TTFT, and $0.25/1M input pricing ($0.025/1M cached reads).
