Head-to-head · Google vs Google
Gemini 3.1 Pro vs Gemini 3.8 Flash
Quick answer: Gemini 3.1 Pro stands out for strong multimodal coverage. Gemini 3.8 Flash stands out for strong quality for a fast, low-cost model. Reviewed September 2026.
Overview
Gemini 3.1 Pro: Gemini 3.1 Pro, released by Google in February 2026, is a multimodal model with strong agentic capabilities. It is listed at $2 and $12 per million tokens for prompts up to 200,000 tokens ($4 and $18 above that) and is offered in preview on the Gemini API.
Gemini 3.8 Flash: Gemini 3.8 Flash, released on 2 September 2026, is Google's newest Flash model, aimed at long-horizon engineering and agent tasks. It is priced at $0.75 and $3.75 per million tokens, a rate Google lists through 31 December 2026, after which it rises to $1.50 and $7.50.
At a glance
| Dimension | Gemini 3.1 Pro | Gemini 3.8 Flash |
|---|---|---|
| Vendor | ||
| Starting price | API: $2 in / $12 out per M tokens | API: $0.75 in / $3.75 out per M tokens |
| Pricing model | Paid | Paid |
| Free tier | No | No |
| Category | Generative AI | Generative AI |
Strengths and limits
Gemini 3.1 Pro
- Strong multimodal coverage
- Deep Google ecosystem integration
- Competitive price for a Pro-tier model
Watch out for
- Listed as a preview model on the pricing page
- Google has said Gemini 4 is coming
- Output style can vary between interfaces
Gemini 3.8 Flash
- Strong quality for a fast, low-cost model
- Well suited to agentic and coding workflows
- Backed by Google's multimodal stack
Watch out for
- Listed price applies through 31 December 2026
- Below Pro-tier models on the hardest reasoning
- Very new, so limited independent evaluations
Key features
Gemini 3.1 Pro
- Multimodal understanding across text, images, audio and video
- Agentic and tool-use capabilities
- Tiered pricing for prompts over 200,000 tokens
- Available through the Gemini API and Google Cloud
Gemini 3.8 Flash
- Latest Flash-tier Gemini model
- Built for agents and long-horizon engineering tasks
- Low per-token price
- Available through the Gemini API
Pricing compared
Gemini 3.1 Pro is priced by usage rather than by seat: API: $2 in / $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Gemini 3.8 Flash is priced by usage rather than by seat: API: $0.75 in / $3.75 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Frequently asked questions
Which is better, Gemini 3.1 Pro or Gemini 3.8 Flash?
It depends on the work. Gemini 3.1 Pro stands out for strong multimodal coverage. Gemini 3.8 Flash stands out for strong quality for a fast, low-cost model.
How do Gemini 3.1 Pro and Gemini 3.8 Flash compare on price?
Gemini 3.1 Pro is priced by usage rather than by seat: API: $2 in / $12 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing. Gemini 3.8 Flash is priced by usage rather than by seat: API: $0.75 in / $3.75 out per M tokens. That means cost scales with how much text you send and receive, so estimate your monthly volume before committing.
Is there a free option between Gemini 3.1 Pro and Gemini 3.8 Flash?
Neither lists a permanent free tier. Look for trials or usage-based pricing to test on real work first.