Gemini 3.1 Pro: token counter & pricing
Google · exact (uses official tokenizer) · pricing as of 2026-05-31.
- Provider
- API model ID
gemini-3.1-pro-preview- Context window
- 1,000,000 tokens
- Input price
- $2.00 per 1M tokens
- Output price
- $12.00 per 1M tokens
- Tokenizer accuracy
- exact (uses official tokenizer)
- Pricing as of
- 2026-05-31
Open the counter to count tokens for Gemini 3.1 Pro in real time.
What is Gemini 3.1 Pro?
Gemini 3.1 Pro is Google's frontier reasoning model, released as a Preview alongside Gemini 3 Flash in April 2026. The most capable Gemini available today on multimodal understanding, agentic capabilities, and "vibe-coding" workflows.
Currently in Preview. Pricing and behavior may change before GA.
How tokens are counted here
Google's official models.countTokens endpoint via our serverless proxy. Exact.
Pricing notes
Tier-based pricing:
- ≤200K input tokens: $2 input / $12 output per 1M (the calculator above uses this tier)
- >200K input tokens: $4 input / $18 output per 1M
Cached input: $0.20/M (≤200k) or $0.40/M (>200k). Cache storage charged at $4.50 per 1M tokens per hour.
For 1,000 input + 200 output: $0.0044 per call, $4,400 per 1M calls at the short-context tier.
When to use Gemini 3.1 Pro
- Frontier Gemini reasoning where you need the next-gen quality bump from 2.5 Pro.
- Long context up to 200K where the short-context tier price applies.
- Multimodal agentic workflows, Gemini 3.x has measurable improvements on tool use and code generation vs the 2.5 family.
When not to use it:
- Production-stable workloads. Preview means pricing/behavior could shift.
- Cost-sensitive workloads, base Gemini 2.5 Pro ($1.25/$10) is 38% cheaper and GA.
- Very long context, above 200K the tier-2 price kicks in; Gemini 2.5 Pro tier-2 ($2.50/$15) is competitive.
Common questions
Gemini 3.1 Pro vs GPT-5.5?
GPT-5.5: $5/$30. Gemini 3.1 Pro: $2/$12 ≤200k. Gemini is dramatically cheaper, 60% cheaper input, 60% cheaper output at the short tier. Google's positioning is "Pro-tier quality at Flash-tier prices." Test on your evals; if Gemini holds quality, the cost gap is real.
Gemini 3.1 Pro vs Claude Opus 4.8?
Opus 4.8: $5/$25. Gemini 3.1 Pro is cheaper on both axes. Claude tends to win on instruction-following nuance; Gemini wins on multimodal and long-context reasoning. Run your own evals.
When does Gemini 3.1 Pro leave Preview?
Google hasn't published a GA date. Track the Gemini API release notes. Preview models can change pricing without notice.
Compare Gemini 3.1 Pro to other models
- Gemini 3 Flash (Google, $0.50/$3.00)
- Gemini 3.1 Flash-Lite (Google, $0.25/$1.50)
- Gemini 2.5 Pro (Google, $1.25/$10.00)
- Gemini 2.5 Flash (Google, $0.30/$2.50)
- Gemini 2.5 Flash-Lite (Google, $0.10/$0.40)
- GPT-4.1 (OpenAI, $2.00/$8.00)
- o3 (OpenAI, $2.00/$8.00)
- Mistral Large (Mistral, $2.00/$6.00)