GPT-5 nano vs Gemini 3.1 Pro
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | GPT-5 nano | Gemini 3.1 Pro |
|---|---|---|
| Provider | OpenAI | |
| Input Price (1M) | $0.05 | $2.00 |
| Output Price (1M) | $0.40 | $12.00 |
| Context Window | 400,000 | 1,000,000 |
Verdict
GPT-5 nano costs $0.05 per 1M input tokens and $0.40 per 1M output tokens. Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. GPT-5 nano is 98% cheaper on input tokens than Gemini 3.1 Pro. For output tokens, GPT-5 nano is the more affordable option at $0.40/1M vs $12.00.
On context window, Gemini 3.1 Pro supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose GPT-5 nano
- ✓ You need the lowest input token cost ($ 0.05/1M)
- ✓ Your workload is output-heavy — GPT-5 nano generates text cheaper
- ✓ You are already integrated with OpenAI
When to choose Gemini 3.1 Pro
- ✓ You need a larger context window (1,000,000 tokens)
- ✓ You are already integrated with Google
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is GPT-5 nano cheaper than Gemini 3.1 Pro? ▼
GPT-5 nano is cheaper on input tokens at $0.05/1M vs $2.00/1M for Gemini 3.1 Pro — a 98% saving.
What is the context window of GPT-5 nano vs Gemini 3.1 Pro? ▼
GPT-5 nano has a 400,000-token context window. Gemini 3.1 Pro has a 1,000,000-token context window. Gemini 3.1 Pro supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: GPT-5 nano or Gemini 3.1 Pro? ▼
The best choice depends on your use case. For cost efficiency on input tokens, GPT-5 nano is the cheaper option. For maximum context length, Gemini 3.1 Pro supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.