Gemini 3.1 Pro vs GPT-6 Astra
A side-by-side look at Gemini 3.1 Pro from Google and GPT-6 Astra from OpenAI: list prices, context windows, licensing and capabilities, with monthly costs worked out for three common workloads.
The short version
- Lower list price: Gemini 3.1 Pro, about 4.4× cheaper on a blended basis (three parts input to one part output).
- Larger context window: GPT-6 Astra (1.05M vs 1M tokens).
- Inputs: Gemini 3.1 Pro accepts text, images, video, audio, pdf; GPT-6 Astra accepts text, images.
- Newer release: GPT-6 Astra (September 3, 2026).
Specs side by side
| Gemini 3.1 Pro | GPT-6 Astra | |
|---|---|---|
| Provider | OpenAI | |
| Released | Feb 19, 2026 | Sep 3, 2026 |
| Status | Preview | Current |
| Weights and license | Closed Proprietary | Closed Proprietary |
| Tier | Frontier | Frontier |
| Context window | 1M | 1.05M |
| Max output | 64K | 125K |
| Input per 1M tokens | $2 | $10 |
| Output per 1M tokens | $12 | $50 |
| Cached input per 1M | $0.20 | $1 |
| Input types | Text, Images, Video, Audio, PDF | Text, Images |
| Reasoning mode | Yes | Yes |
| Tool calling | Yes | Yes |
| Parameters | Undisclosed | Undisclosed |
Highlighted cells are better on that line: lower price or larger limit. List prices, standard tier, checked October 10, 2026.
What they cost for real workloads
| Workload (monthly) | Gemini 3.1 Pro | GPT-6 Astra | Difference |
|---|---|---|---|
| Support chatbot30,000 conversations a month, 2,000 input and 400 output tokens each | $264 | $1,200 | Gemini 3.1 Pro saves $936 |
| Document summaries2,000 documents a month, 12,000 input and 800 output tokens each | $67 | $320 | Gemini 3.1 Pro saves $253 |
| Coding agent1,000 tasks a month, 60,000 input and 6,000 output tokens each | $192 | $900 | Gemini 3.1 Pro saves $708 |
Standard rates without caching or batch discounts. Try your own volumes.
Choose Gemini 3.1 Pro if
- you mainly need it for multimodal, which Google emphasizes for this model
- cost per token is a deciding factor
- your inputs include audio, pdf, video
- 1,048,576-token input limit and 65,536-token output limit
- accepts text, image, video, audio and PDF input
Choose GPT-6 Astra if
- you mainly need it for agents, which OpenAI emphasizes for this model
- you need more than 1M tokens of context in one request
- 1.05M-token context window and 128K-token output limit
- reasoning effort from low to max
Our take
Both are positioned for coding, long documents, reasoning. On list price the gap is about 4.4×, which matters most for high-volume, input-heavy workloads. Quality differences shift with every release, so treat this page as a shortlist tool: run 20-50 of your real tasks through both, score the outputs, and divide the bill by the number of tasks each one got right.
Read the full profiles: Gemini 3.1 Pro and GPT-6 Astra. For help designing that test, see how to read LLM benchmarks.
Frequently asked questions
Which is cheaper, Gemini 3.1 Pro or GPT-6 Astra?
Gemini 3.1 Pro has the lower list price: $2 input and $12 output per million tokens, versus $10 and $50. Discounts for caching and batch processing can change the real bill, so price your own token mix.
Which has the bigger context window?
GPT-6 Astra accepts 1.05M tokens, compared with 1M for Gemini 3.1 Pro.
Can I run Gemini 3.1 Pro or GPT-6 Astra on my own hardware?
Gemini 3.1 Pro is closed, so only through hosted APIs. GPT-6 Astra is closed, so only through hosted APIs.
Is Gemini 3.1 Pro better than GPT-6 Astra?
It depends on the task. Public benchmarks and arena rankings move with every release and rarely match a specific workload. Use the specs here to shortlist, then test both on your own prompts and compare accuracy, latency and cost per correct answer.
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