Sim is the open-source AI workspace where teams build, deploy, and manage AI agents. This page compares Gemini 3.1 Pro Preview and Gemini 2.5 Pro on API pricing per 1M tokens, context window, max output, and capabilities. Both models are available in the Sim Agent block, and each Agent block in a Sim agent can use a different model.
API model comparison
Gemini 3.1 Pro Preview vs Gemini 2.5 Pro
Gemini 2.5 Pro is 1.4× cheaper than Gemini 3.1 Pro Preview: 1,000 agent calls with 10k input and 1k output tokens each cost $22.5 versus $32 at standard rates.
Gemini 3.1 Pro Preview charges $2 input and $12 output per 1M tokens; Gemini 2.5 Pro charges $1.25 and $10.
Both models have a 1.05M token context window.
Both can generate up to 66k output tokens per response.
Both support configurable reasoning and tool choice control in Sim.
Pricing, context window, and capabilities
API prices are per 1M tokens. Pricing last updated .
| Metric | Gemini 3.1 Pro Preview | Gemini 2.5 Pro |
|---|---|---|
| Provider | ||
| Input price | $2/1M | $1.25/1M |
| Cached input | $0.2/1M | $0.125/1M |
| Output price | $12/1M | $10/1M |
| Long-context pricing | Above 200k input tokens, the full request is priced at $4/1M input tokens, $0.4/1M cached input tokens, and $18/1M output tokens. | Above 200k input tokens, the full request is priced at $2.5/1M input tokens, $0.25/1M cached input tokens, and $15/1M output tokens. |
| Context window | 1.05M tokens | 1.05M tokens |
| Released | Feb 19, 2026 | Mar 25, 2025 |
| Temperature | 0 to 2 | 0 to 2 |
| Reasoning effort | Not supported | Not supported |
| Verbosity | Not supported | Not supported |
| Thinking levels | low, medium, high (default: high) | low, medium, high (default: high) |
| Structured outputs | Supported | Supported |
| Tool choice | Supported | Supported |
| Computer use | Not supported | Not supported |
| Deep research | Not supported | Not supported |
| Memory support | Supported | Supported |
| Max output tokens | 66k | 66k |
Use Gemini 3.1 Pro Preview or Gemini 2.5 Pro in a Sim agent
Both models are available in the Sim Agent block. Pick either one from the model picker, and each Agent block in the same agent can use a different model.
Frequently asked questions
Gemini 2.5 Pro is 1.4× cheaper than Gemini 3.1 Pro Preview: 1,000 agent calls with 10k input and 1k output tokens each cost $22.5 versus $32 at standard rates. Gemini 3.1 Pro Preview charges $2 input and $12 output per 1M tokens; Gemini 2.5 Pro charges $1.25 and $10.
