Text generation / Google

Gemini 3.1 Pro (preview)

Gemini 3.1 Pro Preview is a Google model for complex reasoning, software development, and agents that carry out tasks across multiple steps. It updates Gemini 3 Pro with an emphasis on reliable tool use and factual consistency. Its published context window is 1,000,000 tokens. The advertised input rate is $2.00 per million input tokens. The advertised output rate is $12.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

api id: google/gemini-3.1-pro-preview

model as markdown ↗

how much does gemini 3.1 pro (preview) cost?

published base api rates · usd per 1m tokens

input
$2.00
output
$12.00
cache read
$0.20
long-context rates · usd per 1m tokens
total inputinputoutputcache read
over 200,000 tokens$4.00$18.00$0.40

crossing a threshold applies that bracket to the whole request. cache creation can have a separate charge.

rates are published by the impossibl api. balance-purchase fees, taxes, tool charges, and workspace-specific pricing are separate.

specifications & capabilities

creator
Google
model type
Text generation
context window
1m tokens
maximum output
not published in the catalog
input types
text, image, audio, video
output types
text
tool calling
not verified in the catalog

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports.

published endpoint

/v1/chat/completions

see the model documentation for integration details.

estimate your usage

estimate your api cost

estimate text token usage for your workload. all amounts are in usd.

token workload

total input, including cached tokens

include billable reasoning tokens

the same token usage in each request

a subset of total input, never additional tokens

Gemini 3.1 Pro (preview)

$8.00

estimated usage cost

1,000 requests × (1,000 uncached input × $2.00 + 500 output × $12.00) / 1,000,000 = $8.00

base rates: up to 200,000 input tokens per request, inclusive.

estimates use published impossibl api usage rates. configured billing adjustments, funding fees, taxes, and custom workspace rates are excluded and may change the final amount.

image and audio usage, cache creation, and additional tool charges are excluded. reasoning tokens count as billable output, even when they are not visible in the response.

compare more Text generation models

independent benchmarks

Results from Artificial Analysis. Each configuration is listed separately. These evaluations describe the tested model configuration; performance and costs can differ on Impossibl. Last checked 2026-09-11.

Gemini 3.1 Pro Preview
BenchmarkScore
Intelligence Index30.36
Omniscience Index31.88
GPQA94.14%
Humanity’s Last Exam47.03%
SciCode58.68%
CritPt17.71%
Terminal-Bench v2.173.78%
Terminal-Bench v4.04.04%
Terminal-Bench Hard53.79%
AA-LCR82.00%
Multilingual LCR15.56%
Harvey LAB58.85%
GDPval Elo903.94
GDP.pdf All-pass17.80%
AutomationBench Partial35.43%
AnalystAgent41.25%
MMMU-Pro82.43%
IFBench77.14%
Tau295.61%
Tau Banking21.44%
APEX-Agents32.01%
ITBench30.33%
coding index (API)68.8
agentic index (API)10.3
intelligence index (API)30.4

Unmeasured scores are omitted. API values retain their source units.

view source ↗

all source data and breakdowns (JSON) ↗

frequently asked questions

What is Gemini 3.1 Pro (preview)?

Gemini 3.1 Pro Preview is a Google model for complex reasoning, software development, and agents that carry out tasks across multiple steps. It updates Gemini 3 Pro with an emphasis on reliable tool use and factual consistency.

How much does Gemini 3.1 Pro (preview) cost?

Gemini 3.1 Pro (preview) costs $2.00 per million input tokens and $12.00 per million output tokens through the Impossibl API. Cache reads cost $0.20 per million tokens. These base rates apply through 200,000 total input tokens per request. Above 200,000 input tokens, the long-context rates in the pricing table apply to the whole request. All rates are in USD.

view the pricing table ↑

What is the context length of Gemini 3.1 Pro (preview)?

Gemini 3.1 Pro (preview) has a 1,000,000-token context window through the Impossibl API.

What inputs and outputs does Gemini 3.1 Pro (preview) support?

Gemini 3.1 Pro (preview) accepts text, image, audio, and video as input. Gemini 3.1 Pro (preview) returns text.

How do I use Gemini 3.1 Pro (preview) through an API?

Gemini 3.1 Pro (preview) is available through the Impossibl API. Use google/gemini-3.1-pro-preview as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was Gemini 3.1 Pro (preview) released?

Google released Gemini 3.1 Pro (preview) on February 19, 2026.

sources & coverage

this page describes Gemini 3.1 Pro (preview) as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes.

view the source catalog ↗

model descriptions and release dates, where available, use the creator sources linked in the faq. api prices and limits use the impossibl catalog. benchmark results, where available, are credited to Artificial Analysis in the benchmarks section. report a correction →