Gemini 3.1 Pro — Spécifications
| Développeur | |
|---|---|
| Type | LLM (multimodale) |
| Modalité | Texte, image, audio, vidéo → Texte |
| Paramètres | Non divulgué |
| Fenêtre de contexte | 1,05 million |
| Sortie maximale | 65 K |
| Licence | Propriétaire |
| Poids ouverts | Non |
| Publié | 2026 |
| Prix de l’entrée | 2,00 $ / 1 million |
| Prix de la sortie | 12,00 $ / 1 million |
| Fournisseurs d'API | Google AI Studio, Vertex AI |
What is Gemini 3.1 Pro?
Gemini 3.1 Pro is Google’s Pro-tier multimodal model, combining strong reasoning and
agentic ability with a context window of roughly 1.05M tokens. It is served through Google AI
Studio and Vertex AI at $2 in / $12 out per million tokens.
The pricing footnote matters more than the headline rate: prompts above 200K tokens are
billed at roughly double the input rate. For a model whose main selling point is a million-token
context, that creates a sharp cost cliff exactly where you would want to use it. Budgeting a
long-context feature on the $2 figure will understate the bill substantially once real user
prompts start crossing 200K. The practical response is to design around the threshold —
aggressive retrieval and reranking so that prompts stay under it — or to compare against a
model that charges one flat rate across the whole window, such as Claude Opus 4.8. Note too
that Gemini 3.5 Flash sits below 3.1 Pro on price while outperforming it on coding and
agentic benchmarks, so 3.1 Pro is worth choosing for its multimodal breadth rather than by
default.
Gemini 3.1 Pro pricing: API cost per 1M tokens
| Entrée (par million de jetons) | $2.00 |
|---|---|
| Sortie (par million de jetons) | $12.00 |
| Output/input ratio | 6× |
| Blended (4:1 in:out) | $4.00 per 1M tokens |
What Gemini 3.1 Pro costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Charge de travail | Jetons/mois | Cost / month |
|---|---|---|
| Projet secondaire | 1 million en entrée / 0,25 million en sortie | $5.00 |
| Petite équipe | 20 millions en entrée / 5 millions en sortie | $100 |
| Production | 200 millions en entrée / 50 millions en sortie | $1,000 |
Run your own numbers in the Calculateur de coûts des API IA.
Cheaper alternatives to Gemini 3.1 Pro
| Modèle | Coût combiné par million de dollars | You save |
|---|---|---|
| GLM 5.2 ouverte | $2.00 | 50% cheaper |
| Gemini 3.5 Flash | $3.00 | 25% cheaper |
| DeepSeek V4-Pro ouverte | $0.522 | 87% cheaper |
Questions fréquemment posées
How much does Gemini 3.1 Pro cost per 1M tokens?
Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $4.00 per 1M tokens.
How much does Gemini 3.1 Pro cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $100 on Gemini 3.1 Pro. A side project (1M in / 0.25M out) costs roughly $5.00.
What is a cheaper alternative to Gemini 3.1 Pro?
GLM 5.2 is the strongest cheaper option in our database at $2.00 per 1M blended — about 50% less than Gemini 3.1 Pro. It is also open-weight, so self-hosting is an option.
Can I run Gemini 3.1 Pro locally?
No. Gemini 3.1 Pro is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does Gemini 3.1 Pro charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. Gemini 3.1 Pro charges 6× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
See every Gemini model priced side by side: Gemini API pricing.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the Base de données des modèles d'IA ou le Classement des grands modèles linguistiques (LLM).
