Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro Preview
Head-to-head specifications
| Metric | Gemini 3.1 Flash-Lite | Gemini 3.1 Pro Preview | Difference |
|---|---|---|---|
| Intelligence Index | 28.0 | 46.0 | -39.1% |
| Coding Index | 34.7 | 68.8 | -49.6% |
| Agentic Index | 6.2 | 21.4 | — |
| Context window | 1M tokens | 1M tokens | — |
| Blended price ($/1M tokens) | $0.22 | $0.91 | -75.8% |
| Output speed (tokens/s) | 278 | 117 | +137.6% |
| Access | Proprietary API | Proprietary API | — |
- Gemini 3.1 Pro Preview leads overall capability (Intelligence Index 46.0 vs 28.0).
- Gemini 3.1 Flash-Lite is the cheaper model to run at $0.22/1M blended tokens — about 4.1× cheaper.
Verdict: Gemini 3.1 Flash-Lite or Gemini 3.1 Pro Preview?
Gemini 3.1 Flash-Lite advantages
- Affordability (+76%)
- Output speed (+58%)
Gemini 3.1 Pro Preview advantages
- General intelligence (+39%)
- Coding ability (+50%)
- Agentic task performance (+71%)
Which should you choose?
- Choose the Gemini 3.1 Flash-Lite if you want the lowest cost per token at scale.
- Choose the Gemini 3.1 Pro Preview if you need the strongest overall reasoning and accuracy.
- Choose the Gemini 3.1 Flash-Lite if low latency and fast generation matter for your application.
Value for money
Gemini 3.1 Flash-Lite offers more intelligence per dollar (2.5× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro Preview: which should you choose?
Gemini 3.1 Flash-Lite — Google multimodal model with an Intelligence Index of 28, a 1M-token context window and a blended price of $0.22/1M tokens.
Gemini 3.1 Pro Preview — Google multimodal model with an Intelligence Index of 46, a 1M-token context window and a blended price of $0.91/1M tokens.
Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro Preview: Gemini 3.1 Pro Preview scores higher on the Intelligence Index. Gemini 3.1 Pro Preview leads overall capability (Intelligence Index 46.0 vs 28.0). Gemini 3.1 Flash-Lite is the cheaper model to run at $0.22/1M blended tokens — about 4.1× cheaper.
Capability: intelligence, coding and agentic work
On the composite Intelligence Index the Gemini 3.1 Pro Preview scores 46.0 versus 28.0. For software development, the Coding Index puts Gemini 3.1 Pro Preview ahead (68.8 vs 34.7). On agentic, multi-step tool-use tasks, Gemini 3.1 Pro Preview measures stronger. Composite indices summarize many evaluations, but always test on your own workload before committing.
Context window and speed
The Gemini 3.1 Flash-Lite accepts up to 1 million tokens per request, which sets how much documentation, transcript or code it can reason over at once. In measured throughput, Gemini 3.1 Flash-Lite generates faster (278 vs 117 tokens/s), which matters for interactive apps and high-volume pipelines.
Pricing and access
At blended per-token rates, Gemini 3.1 Flash-Lite is the cheaper model to run ($0.22 vs $0.91 per 1M tokens). Gemini 3.1 Flash-Lite is proprietary api and Gemini 3.1 Pro Preview is proprietary api. Open-weight models can be self-hosted, trading per-call cost for infrastructure you manage; for production also weigh rate limits, throughput and data-residency requirements.
The verdict
Both are credible choices in the ai model comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the Gemini 3.1 Flash-Lite better than the Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview takes the overall edge, though Gemini 3.1 Flash-Lite wins in specific areas worth weighing. Gemini 3.1 Pro Preview leads overall capability (Intelligence Index 46.0 vs 28.0).
What is the main difference between the Gemini 3.1 Flash-Lite and the Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview leads overall capability (Intelligence Index 46.0 vs 28.0). Gemini 3.1 Flash-Lite is the cheaper model to run at $0.22/1M blended tokens — about 4.1× cheaper.
Which is better value?
Gemini 3.1 Flash-Lite offers more intelligence per dollar (2.5× the Intelligence-Index-per-cost of the alternative), making it the stronger value for high-volume use.
Which should I choose?
Choose the Gemini 3.1 Flash-Lite if you want the lowest cost per token at scale. Choose the Gemini 3.1 Pro Preview if you need the strongest overall reasoning and accuracy.
Methodology
Large language models are compared on independent leaderboard metrics: an Intelligence Index (a composite of reasoning and knowledge evaluations), Coding and Agentic indices where measured, community arena Elo, maximum context window, a blended API price per million tokens (weighted across cache-hit, input and output rates), and measured output speed in tokens per second. Where a model ships multiple reasoning-effort variants, we report its strongest variant. Benchmarks capture only part of real-world quality, which also depends on tool use, latency, safety and task fit — and this space moves quickly, so figures reflect the leaderboard snapshot on the page date.