Gemini 3.1 Pro vs GPT-5.6 Sol: pricing and benchmarks
Gemini 3.1 Pro is 50% cheaper on input tokens ($2.00 vs $4.00 per 1M). Gemini 3.1 Pro is 40% cheaper on output tokens ($12.00 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.1 Pro costs $1,160 a month versus $2,200 for GPT-5.6 Sol, 47% less. GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index vs 155.0 for Gemini 3.1 Pro.
Prices verified September 14, 2026.
Which should you choose?
GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index vs 155.0 for Gemini 3.1 Pro.
GPT-5.6 Sol scores 72.7% on DeepSWE vs 11.7% for Gemini 3.1 Pro.
GPT-5.6 Sol scores 89.1% on FrontierMath (Tiers 1–3) vs 59.6% for Gemini 3.1 Pro.
Gemini 3.1 Pro costs $4.50 per 1M tokens (3:1 input-to-output mix) vs $8.00 for GPT-5.6 Sol, 44% less.
A trade-off: GPT-5.6 Sol is 6.8 ECI points more capable but costs 1.8x as much as Gemini 3.1 Pro.
Pricing and specs
| Gemini 3.1 Pro | GPT-5.6 Sol | |
|---|---|---|
| Provider | OpenAI | |
| API model ID | gemini-3.1-pro-preview | gpt-5.6-sol |
| Input / 1M tokens | $2.00 | $4.00 |
| Cached input / 1M tokens | $0.20 | $0.40 |
| Output / 1M tokens | $12.00 | $20.00 |
| Long-context rates | $4.00 in / $18.00 out above 200K prompt tokens | $8.00 in / $30.00 out on long-context requests |
| Context window | 1.05M tokens | 1.05M tokens |
| Max output | 66K tokens | 128K tokens |
| Batch discount | — | 50% off |
Benchmarks
| Gemini 3.1 Pro | GPT-5.6 Sol | |
|---|---|---|
| Epoch Capabilities Index | 155.0 | 161.8 |
| GPQA Diamond· Science reasoning | 92.6% | 91.3% |
| FrontierMath (Tiers 1–3)· Advanced math | 59.6% | 89.1% |
| SimpleQA Verified· Factual accuracy | 73.5% | 69.7% |
| ARC-AGI-2· Abstract reasoning | 77.1% | 92.5% |
| DeepSWE· Coding | 11.7% | 72.7% |
| APEX-Agents· Agentic work | 33.5% | 40.0% |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Gemini 3.1 Pro | GPT-5.6 Sol | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $780.00 | $1,400 | Gemini 3.1 Pro 44% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $1,160 | $2,200 | Gemini 3.1 Pro 47% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $536.00 | $992.00 | Gemini 3.1 Pro 46% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Gemini 3.1 Pro vs GPT-5.6 Sol cost calculator
- $1,160/mo$0.02 / request
- GPT-5.6 SolOpenAI$2,200/mo$0.04 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Gemini 3.1 Pro pricing notes
Google’s Gemini 3.1 Pro model, currently offered as a preview.
- Prompts over 200K tokens are billed at $4 input / $18 output per 1M tokens.
- No free tier on the Gemini API.
- Output price includes thinking tokens.
GPT-5.6 Sol pricing notes
OpenAI’s flagship GPT-5.6 model for complex professional work.
- Promotional pricing, available at least through November 21, 2026.
- Cache writes are billed at $5 per 1M tokens.
- Regional (data residency) endpoints add a 10% uplift.
Frequently asked questions
- Is Gemini 3.1 Pro cheaper than GPT-5.6 Sol?
- Gemini 3.1 Pro is 50% cheaper on input tokens ($2.00 vs $4.00 per 1M). Gemini 3.1 Pro is 40% cheaper on output tokens ($12.00 vs $20.00 per 1M). On our document Q&A workload (50,000 questions a month), Gemini 3.1 Pro costs $1,160 a month versus $2,200 for GPT-5.6 Sol, 47% less.
- Which is more capable, Gemini 3.1 Pro or GPT-5.6 Sol?
- GPT-5.6 Sol scores 161.8 on the Epoch Capabilities Index vs 155.0 for Gemini 3.1 Pro.
- How much does Gemini 3.1 Pro cost per 1M tokens?
- Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens, and $0.20 per 1M cached input tokens on Google’s standard tier.
- How much does GPT-5.6 Sol cost per 1M tokens?
- GPT-5.6 Sol costs $4.00 per 1M input tokens and $20.00 per 1M output tokens, and $0.40 per 1M cached input tokens on OpenAI’s standard tier.
- Which has the larger context window, Gemini 3.1 Pro or GPT-5.6 Sol?
- GPT-5.6 Sol has the larger context window: 1.05M tokens versus 1.05M for Gemini 3.1 Pro.