Gemini 3.1 Pro vs Gemini 3.5 Flash-Lite
Pricing verdict: Gemini 3.1 Pro vs Gemini 3.5 Flash-Lite: Gemini 3.5 Flash-Lite is cheaper for input-heavy usage ($0.30/M vs $2.00/M input tokens), while Gemini 3.1 Pro is better for long-context tasks (1,000,000 tokens).
Direct answer: choose Gemini 3.5 Flash-Lite for lower token spend and choose Gemini 3.1 Pro when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Gemini 3.1 Pro
Gemini 3.5 Flash-Lite
Cost Differences
Gemini 3.5 Flash-Lite costs less than Gemini 3.1 Pro
Quick Recommendation
Winner for direct API pricing: Gemini 3.5 Flash-Lite. At the default workload, Gemini 3.5 Flash-Lite saves about $19.35/month ($235.425/year) versus Gemini 3.1 Pro.
Feature Comparison
| Feature | Gemini 3.1 Pro | Gemini 3.5 Flash-Lite |
|---|---|---|
| Provider | ||
| Input Price | $2.00/1M tokens | $0.30/1M tokens |
| Output Price | $12.00/1M tokens | $2.50/1M tokens |
| Context Window | 1,000,000 tokens | 1,000,000 tokens |
| Max Output | 65,536 tokens | 65,536 tokens |
| Category | flagship | efficient |
| Capabilities | textvisionaudiovideocodereasoning | textvisionaudiovideocodereasoning |
| Release Date | 2/19/2026 | 7/21/2026 |
Gemini 3.1 Pro vs Gemini 3.5 Flash-Lite: Which Should You Choose?
Choosing between Gemini 3.1 Pro and Gemini 3.5 Flash-Lite depends on your priorities: cost efficiency, context length, or raw capability. Gemini 3.5 Flash-Lite is the more affordable option at $0.30/1M input tokens — 85% cheaper than Gemini 3.1 Pro.
These models target different tiers: Gemini 3.1 Pro is a flagship model while Gemini 3.5 Flash-Lite is efficient. This means they're optimized for different workloads. Gemini 3.1 Pro is built for complex tasks that require deeper reasoning, while Gemini 3.5 Flash-Lite offers better value for routine operations.
Output costs matter too. Gemini 3.1 Pro charges $12.00/1M output tokens vs $2.50 for Gemini 3.5 Flash-Lite. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Gemini 3.5 Flash-Lite has the edge here at $2.50/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose Gemini 3.1 Pro when:
- • You're already using Google's API ecosystem
Choose Gemini 3.5 Flash-Lite when:
- • Budget is a primary concern
- • You're already using Google's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Pros and Caveats at a Glance
Gemini 3.1 Pro
- • Input pricing: $2.00/M tokens
- • Output pricing: $12.00/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 65,536 tokens
Watch out for
- • Higher input cost than Gemini 3.5 Flash-Lite
- • Higher output cost than Gemini 3.5 Flash-Lite
Gemini 3.5 Flash-Lite
- • Input pricing: $0.30/M tokens
- • Output pricing: $2.50/M tokens
- • Context window: 1,000,000 tokens
- • Max output: 65,536 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Gemini 3.1 Pro (Google)
Gemini 3.5 Flash-Lite (Google)
Start using Gemini 3.1 Pro today
Sign Up for Google →Start using Gemini 3.5 Flash-Lite today
Sign Up for Google →Frequently Asked Questions
Which is cheaper, Gemini 3.1 Pro or Gemini 3.5 Flash-Lite?▼
What is the context window difference between Gemini 3.1 Pro and Gemini 3.5 Flash-Lite?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Related Comparisons
Related Articles
Learn when to pick each model, then compare live pricing scenarios.