💰 Unit Cost Winner Gemini 3.8 Flash $0.25/1M in · $1.50/1M out
⚡ Latency & Speed Winner Gemini 3.8 Flash 105ms TTFT · 210 tok/s
💻 Coding (SWE) Winner Gemini 3.8 Flash 68.5% SWE-bench · 94.2% HumanEval
🧠 STEM Reasoning Winner Gemini 3.8 Flash 79.2% GPQA · 95.1% MATH-500

Which model is better: Gemini 2.5 Flash or Gemini 3.8 Flash?

Gemini 3.8 Flash is 16.7% cheaper for input tokens ($0.25 vs. $0.30 per 1M tokens) and $1.50 vs. $2.50 for output tokens (1.2x cost advantage). In terms of operational performance, Gemini 3.8 Flash delivers lower response latency at 105ms TTFT (5ms faster than Gemini 2.5 Flash) with 210 vs. 180 tok/s throughput. Gemini 3.8 Flash leads coding evaluations at 68.5% SWE-bench Verified vs. 58.0% for Gemini 2.5 Flash and 79.2% vs. 70.5% on GPQA Diamond.
Verified daily via automated API latency tests and official documentation.

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 2.5 Flash Gemini 3.8 Flash Net Delta / Advantage
Input Cost / 1M Tokens $0.30 $0.25 Gemini 3.8 Flash is 1.2x cheaper
Output Cost / 1M Tokens $2.50 $1.50 Gemini 3.8 Flash (40.0% lower)
Prompt Cache Read / 1M $0.030 $0.025 Gemini 3.8 Flash is 1.2x cheaper
Prompt Cache Write / 1M $0.30 $0.25 Gemini 3.8 Flash is 1.2x cheaper
Context Window (Max Output) 1,049k (66k out) 1,049k (66k out) Equal Context Window
Avg TTFT Response Latency 110ms 105ms Gemini 3.8 Flash (5ms faster)
Generation Speed (Throughput) 180 tok/s 210 tok/s Gemini 3.8 Flash (+30 tok/s faster)
SWE-bench Verified (Coding) 58% 68.5% Gemini 3.8 Flash (+10.5% lead)
GPQA Diamond (PhD STEM) 70.5% 79.2% Gemini 3.8 Flash (+8.7% lead)
MMLU-Pro (Multi-Discipline) 82% 87.4% Gemini 3.8 Flash (+5.4% lead)
MATH-500 (Quantitative Logic) 89% 95.1% Gemini 3.8 Flash (+6.1% lead)
Inference Value Score (IVR) 66.6 / 100 74 / 100 Gemini 3.8 Flash (+7.4 pts)

Interactive Monthly Token Economics & ROI Forecaster

Model production workloads across prompt, completion, and cached context tokens, or switch models on the fly.

25.0M Tokens
500K 50M 250M 500M+
5.0M Tokens
100K 25M 75M 150M+
50% Cached
0% (Uncached) 25% 50% (Typical Agent) 95% Max

Estimated Monthly Spend

Gemini 2.5 Flash $16.63

$0.30/1M in · $2.50/1M out

Prompt Cache: $0.030/1M read · $0.30/1M write

Gemini 3.8 Flash $10.94

$0.25/1M in · $1.50/1M out

Prompt Cache: $0.025/1M read · $0.25/1M write

Projected Monthly Cost Reduction
$5.69 / mo
(34.2% lower cost with Gemini 3.8 Flash)
Open Full Matchup Analysis →
A

When to Choose Gemini 2.5 Flash

Choose Gemini 2.5 Flash (Google) for cost-efficient 1M-context summarization, multimodal extraction, and interactive assistants — offering a 1,048k context window, 110ms TTFT, and $0.30/1M input pricing ($0.030/1M cached reads).

B

When to 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).

Related Questions & Decision Factors

Which is cheaper: Gemini 2.5 Flash or Gemini 3.8 Flash?

Gemini 3.8 Flash is cheaper at $0.25/1M input tokens ($1.50/1M output) compared to $0.30/1M input ($2.50/1M output) for Gemini 2.5 Flash.

Which model has lower TTFT latency and higher tok/s throughput: Gemini 2.5 Flash or Gemini 3.8 Flash?

Gemini 3.8 Flash delivers faster first-token latency at 105ms TTFT (210 tok/s throughput) compared to 110ms TTFT (180 tok/s) for Gemini 2.5 Flash.

How do Gemini 2.5 Flash and Gemini 3.8 Flash compare on SWE-bench coding and GPQA Diamond reasoning?

On SWE-bench Verified software engineering, Gemini 2.5 Flash scores 58% versus 68.5% for Gemini 3.8 Flash. On GPQA Diamond graduate-level STEM reasoning, Gemini 2.5 Flash scores 70.5% versus 79.2% for Gemini 3.8 Flash (and 89% vs 95.1% on MATH-500).

When should you choose Gemini 2.5 Flash?

Choose Gemini 2.5 Flash (Google) for cost-efficient 1M-context summarization, multimodal extraction, and interactive assistants — offering a 1,048k context window, 110ms TTFT, and $0.30/1M input pricing ($0.030/1M 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).

Explore High-Priority Related Model Matchups