Gemini 2.5 Pro vs Gemini 3.5 Flash
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for Gemini 2.5 Pro and Gemini 3.5 Flash.
Gemini 2.5 Pro
Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks. It employs “thinking” capabilities, enabling it to reason through responses with enhanced accuracy...
Gemini 3.5 Flash
Gemini 3.5 Flash is Google's high-efficiency multimodal model, bringing near-Pro level coding and reasoning at Flash-tier cost and speed. It is highly optimized for coding proficiency and parallel agentic execution...
Technical Specifications
| Specification | Gemini 2.5 Pro | Gemini 3.5 Flash |
|---|---|---|
| Provider | ||
| Context Window | 1,048,576 tokens | 1,048,576 tokens |
| Agent Suitability | 90/100 | 88/100 |
| Time to First Token (TTFT) | 450 ms | 200 ms |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-06-17 | 2026-05-19 |
API Pricing Comparison
Input Price per Million Tokens
Gemini 2.5 Pro
$1.25
Gemini 3.5 Flash
$1.50
Output Price per Million Tokens
Gemini 2.5 Pro
$10.00
Gemini 3.5 Flash
$9.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
Gemini 2.5 Pro Quirks & Gotchas
- ▸Legacy model — migrate to Gemini 3.1 Pro for better tool calling and lower latency
Gemini 3.5 Flash Quirks & Gotchas
- ▸Excellent multimodal performance — native video understanding
- ▸Tool calling via Google's native function_declarations in Vertex AI