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Gemini 2.5 Pro vs Gemini 3.5 Flash-Lite: pricing and benchmarks

Gemini 3.5 Flash-Lite is 76% cheaper on input tokens ($0.30 vs $1.25 per 1M). Gemini 3.5 Flash-Lite is 75% cheaper on output tokens ($2.50 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.5 Flash-Lite costs $195.00 a month versus $800.00 for Gemini 2.5 Pro, 76% less. Roughly tied. Gemini 2.5 Pro scores 145.3 and Gemini 3.5 Flash-Lite scores 145.1 on the Epoch Capabilities Index, and their confidence intervals overlap.

Prices verified September 14, 2026.

Which should you choose?

Overall capability
Too close to call

Roughly tied. Gemini 2.5 Pro scores 145.3 and Gemini 3.5 Flash-Lite scores 145.1 on the Epoch Capabilities Index, and their confidence intervals overlap.

Advanced math
Too close to call

About even on FrontierMath (Tiers 1–3): 24.6% for Gemini 2.5 Pro and 26.0% for Gemini 3.5 Flash-Lite.

Price
Gemini 3.5 Flash-Lite

Gemini 3.5 Flash-Lite costs $0.85 per 1M tokens (3:1 input-to-output mix) vs $3.438 for Gemini 2.5 Pro, 75% less.

Best value
Gemini 3.5 Flash-Lite

Gemini 3.5 Flash-Lite delivers statistically similar overall capability for 75% less.

Pricing and specs

Gemini 2.5 ProGemini 3.5 Flash-Lite
ProviderGoogleGoogle
API model IDgemini-2.5-progemini-3.5-flash-lite
Input / 1M tokens$1.25$0.30
Cached input / 1M tokens$0.125$0.03
Output / 1M tokens$10.00$2.50
Long-context rates$2.50 in / $15.00 out above 200K prompt tokens
Context window1.05M tokens1.05M tokens
Max output66K tokens66K tokens
Batch discount50% off

Benchmarks

Gemini 2.5 ProGemini 3.5 Flash-Lite
Epoch Capabilities Index145.3145.1
GPQA Diamond· Science reasoning80.4%77.8%
FrontierMath (Tiers 1–3)· Advanced math24.6%26.0%
SimpleQA Verified· Factual accuracy
ARC-AGI-2· Abstract reasoning4.9%10.3%
DeepSWE· Coding
APEX-Agents· Agentic work6.6%

Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks

Monthly cost for real workloads

WorkloadGemini 2.5 ProGemini 3.5 Flash-LiteDifference
Support chatbot
100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each.
$587.50$145.00Gemini 3.5 Flash-Lite 75% cheaper
Document Q&A (RAG)
50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each.
$800.00$195.00Gemini 3.5 Flash-Lite 76% cheaper
Coding agent
10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens.
$385.00$94.40Gemini 3.5 Flash-Lite 75% cheaper

Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.

Gemini 2.5 Pro vs Gemini 3.5 Flash-Lite cost calculator

Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.

Gemini 2.5 Pro pricing notes

Google’s previous-generation Pro model.

  • Prompts over 200K tokens are billed at $2.50 input / $15 output per 1M tokens.
  • Output price includes thinking tokens.
Google official pricing ↗

Gemini 3.5 Flash-Lite pricing notes

Google’s lowest-cost Gemini 3.5 model for high-volume work.

  • The same input price applies to text, image, video and audio.
  • Output price includes thinking tokens.
Google official pricing ↗

Frequently asked questions

Is Gemini 2.5 Pro cheaper than Gemini 3.5 Flash-Lite?
Gemini 3.5 Flash-Lite is 76% cheaper on input tokens ($0.30 vs $1.25 per 1M). Gemini 3.5 Flash-Lite is 75% cheaper on output tokens ($2.50 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.5 Flash-Lite costs $195.00 a month versus $800.00 for Gemini 2.5 Pro, 76% less.
Which is more capable, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?
Roughly tied. Gemini 2.5 Pro scores 145.3 and Gemini 3.5 Flash-Lite scores 145.1 on the Epoch Capabilities Index, and their confidence intervals overlap.
How much does Gemini 2.5 Pro cost per 1M tokens?
Gemini 2.5 Pro costs $1.25 per 1M input tokens and $10.00 per 1M output tokens, and $0.125 per 1M cached input tokens on Google’s standard tier.
How much does Gemini 3.5 Flash-Lite cost per 1M tokens?
Gemini 3.5 Flash-Lite costs $0.30 per 1M input tokens and $2.50 per 1M output tokens, and $0.03 per 1M cached input tokens on Google’s standard tier.
Which has the larger context window, Gemini 2.5 Pro or Gemini 3.5 Flash-Lite?
Both offer a 1.05M-token context window.

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