Which model is better: Claude 3.5 Sonnet or Gemini 2.5 Flash?

Gemini 2.5 Flash is 90.0% cheaper for input tokens ($0.30 vs. $3.00 per 1M tokens) and $2.50 vs. $15.00 for output tokens (10.0x cost difference). In terms of operational performance, Gemini 2.5 Flash delivers faster response latency with 110ms TTFT (200ms faster than Claude 3.5 Sonnet). Gemini 2.5 Flash leads coding benchmarks at 58.0% SWE-bench vs. 49.0% for Claude 3.5 Sonnet.
Verified daily via automated API latency tests and official documentation.

Verified Performance & Unit Economics Delta

Daily synchronized metrics from synthetic latency endpoints and benchmark evaluations.

Metric / Dimension Claude 3.5 Sonnet Gemini 2.5 Flash Net Delta / Advantage
Input Cost / 1M Tokens $3.00 $0.30 Gemini 2.5 Flash is 10.0x cheaper
Output Cost / 1M Tokens $15.00 $2.50 Gemini 2.5 Flash (83.3% lower)
Prompt Cache Read / 1M $0.300 $0.030 Gemini 2.5 Flash is 10.0x cheaper
Prompt Cache Write / 1M $3.75 $0.30 Gemini 2.5 Flash is 12.5x cheaper
Avg TTFT Response Latency 310ms 110ms Gemini 2.5 Flash (+200ms faster)
SWE-bench Verified (Coding) 49% 58% Gemini 2.5 Flash (+9.0% lead)
Inference Value Score (IVR) 47.3 / 100 66.8 / 100 Gemini 2.5 Flash (+19.5 pts)

Interactive Monthly Token Economics & ROI Forecaster

Model your expected production workload across prompt (input) and completion (output) tokens with prompt caching economics.

Live Calculation Engine
10.0M Tokens
100K 50M 250M 500M+
2.5M Tokens
100K 10M 50M 100M+

Estimated Monthly Spend

Claude 3.5 Sonnet $67.50

$3.00/1M in · $15.00/1M out

Prompt Cache: $0.300/1M read · $3.75/1M write

Gemini 2.5 Flash $9.25

$0.30/1M in · $2.50/1M out

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

Projected Monthly Cost Reduction
$58.25 / mo
(86.3% lower cost with Gemini 2.5 Flash)
A

When to Choose Claude 3.5 Sonnet

Choose Claude 3.5 Sonnet when you need Industry benchmark for complex software engineering, intricate reasoning, and human-like prose composition. and have an infrastructure budget aligned with $3.00/1M tokens.

B

When to Choose Gemini 2.5 Flash

Choose Gemini 2.5 Flash when you need Hybrid reasoning model delivering unmatched price-performance across 1M context with configurable thinking budgets. and prioritize Google ecosystem integration at $0.30/1M tokens.

Related Questions & Decision Factors

Which is cheaper: Claude 3.5 Sonnet or Gemini 2.5 Flash?

Gemini 2.5 Flash is cheaper at $0.30/1M input tokens compared to $3.00/1M for Claude 3.5 Sonnet.

Which model has lower latency: Claude 3.5 Sonnet or Gemini 2.5 Flash?

Gemini 2.5 Flash delivers faster response times with an average TTFT of 110ms vs 310ms for Claude 3.5 Sonnet.

When should you choose Claude 3.5 Sonnet?

Choose Claude 3.5 Sonnet when you need Industry benchmark for complex software engineering, intricate reasoning, and human-like prose composition. and have an infrastructure budget aligned with $3.00/1M tokens.

When should you choose Gemini 2.5 Flash?

Choose Gemini 2.5 Flash when you need Hybrid reasoning model delivering unmatched price-performance across 1M context with configurable thinking budgets. and prioritize Google ecosystem integration at $0.30/1M tokens.

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