gemini-3.1-pro-preview vs gemini-3.5-flash
Side-by-side comparison of gemini-3.1-pro-preview and gemini-3.5-flash: benchmarks, pricing, context window and capabilities. Both are accessible through Requesty's unified API. gemini-3.1-pro-preview outperforms gemini-3.5-flash on 5 of 7 shared benchmarks.
gemini-3.1-pro-preview
Input / 1M
$2.00
Output / 1M
$12.00
Context
1.0M
Model ID
google/gemini-3.1-pro-preview
gemini-3.5-flash
Input / 1M
$1.50
Output / 1M
$9.00
Context
1.0M
Model ID
google/gemini-3.5-flash
Benchmark comparison
Intelligence Indexreasoning
gemini-3.1-pro-preview36.7%
gemini-3.5-flash39.7%
Coding Indexcoding
gemini-3.1-pro-preview68.8%
gemini-3.5-flash70.1%
GPQA Diamondreasoning
gemini-3.1-pro-preview94.1%
gemini-3.5-flash92.2%
Terminal-Bench Hardagentic
gemini-3.1-pro-preview53.8%
gemini-3.5-flash40.9%
τ²-Benchagentic
gemini-3.1-pro-preview95.6%
gemini-3.5-flash95.3%
SciCodecoding
gemini-3.1-pro-preview58.7%
gemini-3.5-flash53.9%
Humanity's Last Examreasoning
gemini-3.1-pro-preview47.0%
gemini-3.5-flash42.7%
Scores sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and don't capture every aspect of model quality.
Pricing & specifications
| gemini-3.1-pro-preview | gemini-3.5-flash | |
|---|---|---|
| Input price / 1M | $2.00 | $1.50 |
| Output price / 1M | $12.00 | $9.00 |
| Context window | 1.0M tokens | 1.0M tokens |
| Max output | 66K tokens | 66K tokens |
| Vision input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Prompt caching | Yes | Yes |
| Computer use | N/A | N/A |
| Provider | Google LLC (Gemini API) | Google LLC (Gemini API) |
Questions people ask
Is gemini-3.1-pro-preview better than gemini-3.5-flash?
gemini-3.1-pro-preview outperforms gemini-3.5-flash on 5 of 7 shared benchmarks. See the benchmark comparison above for specifics: gemini-3.1-pro-preview and gemini-3.5-flash have different strengths across reasoning, coding, math and multimodal tasks.
Which is cheaper, gemini-3.1-pro-preview or gemini-3.5-flash?
gemini-3.5-flash is cheaper. gemini-3.1-pro-preview costs $2.00/$12.00 per 1M input/output tokens, while gemini-3.5-flash costs $1.50/$9.00.
Can I use gemini-3.1-pro-preview and gemini-3.5-flash through the same API?
Yes. Requesty provides a single OpenAI-compatible API that routes to both. Change just the "model" parameter to switch between "google/gemini-3.1-pro-preview" and "google/gemini-3.5-flash", no other code changes needed.
What are the context windows?
gemini-3.1-pro-preview supports up to 1.0M tokens of context. gemini-3.5-flash supports up to 1.0M tokens. Longer context means you can feed larger documents or codebases in a single prompt, though quality often degrades past 128K for most models.
Switch between gemini-3.1-pro-preview and gemini-3.5-flash with one line of code
Requesty provides a single OpenAI-compatible API for 600+ models. Change the model parameter, not your code.