Gemini 3.1 Pro (preview): what it costs to run
The price Google lists for Gemini 3.1 Pro (preview), what a support reply, a document summary and an agent task cost at it, and where that puts it among 37 models.
US dollars per million tokens, standard rate, shortest context band.
- 1,000 support replies
- $10.80
- Cached input
- $0.20
- Context window
- 1,048,576 tokens
- Released
- 19 Feb 2026
- Weights
- Closed
From Google’s own pages, 22 September 2026.
Gemini 3.1 Pro (preview) costs $2 per million input tokens and $12 per million output tokens on Google’s own API, and $0.20 for cached input. At those prices 1,000 support replies cost $10.80, the 9th most expensive of 33 priced models on our list.
What a job costs
Three jobs, 1,000 runs of each, at the list price above, and where each puts Gemini 3.1 Pro (preview) among the 33 models with a list price.
| Job | 1,000 runs | Among 33 |
|---|---|---|
| Support reply3,000 in, 400 out. | $10.80 | 9th most expensive |
| Document summary25,000 in, 1,000 out. | $62.00 | 9th most expensive |
| Agent task80,000 in (70,000 cached), 3,000 out. | $70.00 | 12th most expensive |
The token counts are ours, chosen to look like real work; the prices are Google’s. All three jobs stay under 200,000 tokens a request, below every long-context surcharge on the list.
Gemini 3.1 Pro (preview) on real small-business tasks
What the AIGROW benchmark measured when Gemini 3.1 Pro (preview) was given 20 office tasks, each marked pass or fail by fixed checks.
- Success rate
- 95% of 20 runs passed (95% interval 76 to 99%), 1st of 36 models.
- Cost per 1,000 passes
- $29.67, failed runs included.
- Answer time
- 17 s median, 21 s at the 90th percentile.
- Strongest and weakest
- Appointment scheduling (100% passed) and review replies (0%).
The small print
What the base rate above leaves out, copied from the maker’s pages: surcharges, discounts, promotions and cache pricing.
Preview model, but Google has no GA 3.x Pro and it is widely used. Prompts above 200K tokens: $4 / $18, cached $0.40. Cache storage $4.50 per MTok per hour. Batch 50% off. Max output 65,536.
Gemini 3.1 Pro (preview) against the models it is weighed with
Each comparison puts both list prices side by side and costs the same three jobs on each.
- vs GPT-6 Astra
- OpenAI's newest flagship against Google's strongest model at a fifth of the input price.
- vs Claude Fable 5.1
- Anthropic's most capable model against Google's, with a fivefold gap in input price.
- vs Claude Opus 5
- A common premium choice for writing and analysis, where Gemini costs well under half.
- vs GPT-5.6 Sol
- OpenAI and Google's everyday frontier options, compared on quality per dollar.
- vs Grok 4.7
- Two frontier models with similar input prices and different long-context rules.
Other Google models
| Model | Input | Output | Context | 1,000 replies |
|---|---|---|---|---|
| Gemini 3.1 Flash-LiteGoogle | $0.25 | $1.50 | 1.05M | $1.35 |
| Gemini 3.5 Flash-LiteGoogle | $0.30 | $2.50 | 1.05M | $1.90 |
| Gemini 3.8 FlashGoogle | $0.75 | $3.75 | 1.05M | $3.75 |
| Gemma 4 31BGoogle · open weights | No list price | · | 256K | · |
Where the price comes from
Read on 22 September 2026. Each price is the standard rate for the shortest context band, with no batch or priority discount; long-context surcharges, batch rates and promotions are in each model’s small print. No price was taken from a reseller.
Pay a quarter of list price
AIGROW API credit is metered at the makers’ list prices, and $25 buys $100 of usage. The credit page lists the models it covers; ask about any other before buying.
Prices checked 22 September 2026