Gemini 3.1 Pro API Pricing
Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens on Google's API. Cached input is billed at $0.2 per 1M tokens. Prices are provider list prices in USD, refreshed as sources update; see the Gemini 3.1 Pro model profile for capability scores.
Price List
| Rate | Price (USD) | Notes |
|---|---|---|
| Input | $2.00 | per 1M tokens |
| Output | $12.00 | per 1M tokens |
| Cached input (read) | $0.2 | per 1M tokens |
| Blended input + output | $14.00 | 1M in + 1M out at list price |
| Context window | 1M tokens |
What a Workload Costs
Computed straight from the list prices above — token counts are illustrative workload sizes, not measurements of Gemini 3.1 Pro.
| Workload | Cost | Tokens |
|---|---|---|
| Short chat turn | $0.00800 | 1K in / 500 out |
| Summarize a long document | $0.224 | 100K in / 2K out |
| Agentic coding session | $2.20 | 500K in / 100K out |
| 1M input + 1M output tokens | $14.00 | 1M in / 1M out |
Effective Cost
In AI IQ's scoring, Gemini 3.1 Pro's list price is adjusted by a token-usage multiplier of 0.676 (measured from real benchmark runs), giving an effective cost of $9.47 per 1M input + output tokens. That places it #82 of 117 models on the effective-cost ranking (lower is cheaper). Some models spend far more tokens than others on the same task, so effective cost compares what a unit of work really costs. Method details are on the methodology page; see all models on the cost charts and the falling cost of intelligence over time.
Cheaper Alternatives at Similar Capability
Models with a lower effective cost that score within a few IQ points of Gemini 3.1 Pro (IQ 127), or better.
| Model | Provider | IQ | Effective Cost / 1M |
|---|---|---|---|
| gpt-5.6-luna | OpenAI | 129 | $9.29 |