💰 Unit Cost Winner Gemini 3.5 Flash-Lite $0.075/1M in · $0.30/1M out
⚡ Latency & Speed Winner Gemini 3.5 Flash-Lite 78ms TTFT · 265 tok/s
💻 Coding (SWE) Winner Gemini 2.5 Pro 63.8% SWE-bench · 89.8% HumanEval
🧠 STEM Reasoning Winner Gemini 2.5 Pro 74% GPQA · 95% MATH-500

Which model is better: Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite is 94.0% cheaper for input tokens ($0.07 vs. $1.25 per 1M tokens) and $0.30 vs. $10.00 for output tokens (16.7x cost advantage). In terms of operational performance, Gemini 3.5 Flash-Lite delivers lower response latency at 78ms TTFT (622ms faster than Gemini 2.5 Pro) with 265 vs. 80 tok/s throughput. Gemini 2.5 Pro leads coding evaluations at 63.8% SWE-bench Verified vs. 55.4% for Gemini 3.5 Flash-Lite and 74.0% vs. 68.4% 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 Pro Gemini 3.5 Flash-Lite Net Delta / Advantage
Input Cost / 1M Tokens $1.25 $0.07 Gemini 3.5 Flash-Lite is 16.7x cheaper
Output Cost / 1M Tokens $10.00 $0.30 Gemini 3.5 Flash-Lite (97.0% lower)
Prompt Cache Read / 1M $0.313 $0.015 Gemini 3.5 Flash-Lite is 20.8x cheaper
Prompt Cache Write / 1M $1.25 $0.07 Gemini 3.5 Flash-Lite is 16.7x cheaper
Context Window (Max Output) 1,024k (66k out) 1,049k (33k out) Gemini 3.5 Flash-Lite (1.0x larger context)
Avg TTFT Response Latency 700ms 78ms Gemini 3.5 Flash-Lite (622ms faster)
Generation Speed (Throughput) 80 tok/s 265 tok/s Gemini 3.5 Flash-Lite (+185 tok/s faster)
SWE-bench Verified (Coding) 63.8% 55.4% Gemini 2.5 Pro (+8.4% lead)
GPQA Diamond (PhD STEM) 74% 68.4% Gemini 2.5 Pro (+5.6% lead)
MMLU-Pro (Multi-Discipline) 85.2% 80.1% Gemini 2.5 Pro (+5.1% lead)
MATH-500 (Quantitative Logic) 95% 90.2% Gemini 2.5 Pro (+4.8% lead)
Inference Value Score (IVR) 56.8 / 100 81.5 / 100 Gemini 3.5 Flash-Lite (+24.7 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 Pro $69.53

$1.25/1M in · $10.00/1M out

Prompt Cache: $0.313/1M read · $1.25/1M write

Gemini 3.5 Flash-Lite $2.63

$0.07/1M in · $0.30/1M out

Prompt Cache: $0.015/1M read · $0.07/1M write

Projected Monthly Cost Reduction
$66.91 / mo
(96.2% lower cost with Gemini 3.5 Flash-Lite)
Open Full Matchup Analysis →
A

When to Choose Gemini 2.5 Pro

Choose Gemini 2.5 Pro (Google) for long-context document and video analysis, large codebase ingestion, and multimodal reasoning — offering a 1,024k context window, 700ms TTFT, and $1.25/1M input pricing ($0.312/1M cached reads).

B

When to Choose Gemini 3.5 Flash-Lite

Choose Gemini 3.5 Flash-Lite (Google) for high-frequency data pipelines, real-time routing, large-scale document tagging, and ultra-low-cost conversational assistants — offering a 1,048k context window, 78ms TTFT, and $0.07/1M input pricing ($0.015/1M cached reads).

Related Questions & Decision Factors

Which is cheaper: Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite is cheaper at $0.075/1M input tokens ($0.30/1M output) compared to $1.25/1M input ($10.00/1M output) for Gemini 2.5 Pro.

Which model has lower TTFT latency and higher tok/s throughput: Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?

Gemini 3.5 Flash-Lite delivers faster first-token latency at 78ms TTFT (265 tok/s throughput) compared to 700ms TTFT (80 tok/s) for Gemini 2.5 Pro.

How do Gemini 2.5 Pro and Gemini 3.5 Flash-Lite compare on SWE-bench coding and GPQA Diamond reasoning?

On SWE-bench Verified software engineering, Gemini 2.5 Pro scores 63.8% versus 55.4% for Gemini 3.5 Flash-Lite. On GPQA Diamond graduate-level STEM reasoning, Gemini 2.5 Pro scores 74% versus 68.4% for Gemini 3.5 Flash-Lite (and 95% vs 90.2% on MATH-500).

When should you choose Gemini 2.5 Pro?

Choose Gemini 2.5 Pro (Google) for long-context document and video analysis, large codebase ingestion, and multimodal reasoning — offering a 1,024k context window, 700ms TTFT, and $1.25/1M input pricing ($0.312/1M cached reads).

When should you choose Gemini 3.5 Flash-Lite?

Choose Gemini 3.5 Flash-Lite (Google) for high-frequency data pipelines, real-time routing, large-scale document tagging, and ultra-low-cost conversational assistants — offering a 1,048k context window, 78ms TTFT, and $0.07/1M input pricing ($0.015/1M cached reads).

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