Google: Gemini 3.1 Pro Preview API Pricing
Google: Gemini 3.1 Pro Preview costs $2.00 per 1M input tokens and $12.00 per 1M output tokens (cache reads: $0.200). Context window: 1.0M. Prices verified 2026-10-21 · source
Alternatives to consider
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Cheapest google model — 99% less per month
Rebuilt daily from our snapshot archive — the chart appears once a model has 5+ snapshots of history.
From our own daily snapshot archive — independent of provider announcements.
Intelligence measures reasoning/knowledge/coding benchmarks. A high score with a low blended price = value pick; check the value chart to see where this model lands.
Token economics
| Token type | Price | vs base input |
|---|---|---|
| Standard input | $2.00 | — |
| Cache read | $0.200 | −90% |
| Cache write (5m) | $0.375 | -81% |
| Output | $12.00 | — |
| Web search tool | $14/1k searches | — |
Prompt caching stores repeated context server-side: reads cost far less, but writes carry a one-time premium.
Higher effort = deeper thinking = more reasoning tokens billed as output.
What would Google: Gemini 3.1 Pro Preview cost you per month?
| Workload | Requests/mo | Avg tokens (in/out) | Est. monthly cost |
|---|---|---|---|
| Light chatbot | 10,000 | 800 / 400 | $64.00 |
| Coding agent | 5,000 | 8,000 / 2,000 | $200.00 |
| RAG pipeline | 30,000 | 4,000 / 500 | $420.00 |
| Doc summarizer | 2,000 | 20,000 / 1,000 | $104.00 |
Estimates use list prices without prompt caching. Caching can cut input cost by up to 90% on repeated context.
About Google: Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...
Compare Google: Gemini 3.1 Pro Preview with
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Popular head-to-heads — see all on the comparisons index.
Frequently asked questions
How much does Google: Gemini 3.1 Pro Preview cost?
Google: Gemini 3.1 Pro Preview costs $2.00 per 1M input tokens and $12.00 per 1M output tokens; cached input tokens cost $0.200 per 1M. Verified 2026-10-21 — provider source.
What is the context window?
1.0M tokens, with up to 66K output tokens per response. That's roughly 1311 pages of text in a single request.
Does it support prompt caching?
Yes — cached input is $0.200/1M, about 90% cheaper than standard input. Agents and RAG workloads with repeated context benefit most.
What's a cheaper alternative?
ScaleDown: Summarize saves about 99% on a typical workload with comparable quality.
Official resources
- Google: Gemini 3.1 Pro Preview on OpenRouter — live endpoint, pricing source of record.
- Artificial Analysis leaderboard → — independent intelligence and performance rankings.
- Gemini docs → — first-party model specifications and limits.
- LMArena leaderboard → — independent human-preference rankings.
- Shred your current bill — paste a CSV and see if switching saves money.