GPT-6 Astra vs Gemini 3.1 Pro Preview: API cost
Standard, cached and batch API prices for GPT-6 Astra (OpenAI) and Gemini 3.1 Pro Preview (Google), and what each costs for your usage.
Gemini 3.1 Pro Preview is cheaper than GPT-6 Astra at standard rates, with 5× cheaper input and 4.2× cheaper output.
- Input $300.00
- Cached input $30.00
- Output $450.00
- Input $60.00
- Cached input $6.00
- Output $108.00
Show as a table
| Output tokens | GPT-6 Astra | Gemini 3.1 Pro Preview |
|---|---|---|
| 0 | $10.00 | $2.00 |
| 250 | $22.50 | $5.00 |
| 500 | $35.00 | $8.00 |
| 750 | $47.50 | $11.00 |
| 1,000 | $60.00 | $14.00 |
| Token type | GPT-6 Astra | Gemini 3.1 Pro Preview | |
|---|---|---|---|
| Input | $10 | $2 | Gemini 3.1 Pro Preview is 5× cheaper |
| Cached input | $1 | $0.20 | Gemini 3.1 Pro Preview is 5× cheaper |
| Output | $50 | $12 | Gemini 3.1 Pro Preview is 4.2× cheaper |
| Batch input | $5 | $1 | Gemini 3.1 Pro Preview is 5× cheaper |
| Batch cached input | $0.50 | $0.20 | Gemini 3.1 Pro Preview is 2.5× cheaper |
| Batch output | $25 | $6 | Gemini 3.1 Pro Preview is 4.2× cheaper |
GPT-6 Astra: Long prompts are billed at higher long-context rates.
Gemini 3.1 Pro Preview: Prompts over 200K tokens are billed at a higher rate.
| Workload | GPT-6 Astra | Gemini 3.1 Pro Preview |
|---|---|---|
Support chatbot 2,000 in / 300 out tokens,
1,000 requests a day, 50% cached | $780.00 | $174.00 |
Document summaries 10,000 in / 800 out tokens,
200 requests a day | $840.00 | $177.60 |
Tagging / classifying 400 in / 20 out tokens,
20,000 requests a day | $3,000 | $624.00 |
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Or see GPT-6 Astra pricing, Gemini 3.1 Pro Preview pricing, or compare any two models.
FAQ
Frequently asked questions
Is GPT-6 Astra cheaper than Gemini 3.1 Pro Preview?
Gemini 3.1 Pro Preview is cheaper than GPT-6 Astra at standard rates, with 5× cheaper input and 4.2× cheaper output. Based on standard API rates last checked on 30 Sept 2026.
How much do GPT-6 Astra and Gemini 3.1 Pro Preview cost per million tokens?
GPT-6 Astra: $10 per million input tokens and $50 per million output tokens. Gemini 3.1 Pro Preview: $2 input and $12 output. These are standard rates in USD, before tax, from each provider’s own pricing page.
Which is cheaper with the Batch API?
GPT-6 Astra’s batch rates are $5 input and $25 output per million tokens (50% off); Gemini 3.1 Pro Preview’s batch rates are $1 input and $6 output per million tokens (50% off).
Does prompt caching change the comparison?
GPT-6 Astra charges $1 per million cached input tokens, against $10 for normal input; Gemini 3.1 Pro Preview charges $0.20 per million cached input tokens, against $2 for normal input. Cache write and storage charges are extra and aren’t included here.