Gemini 3.1 Pro Preview vs GPT-5.5
API pricing, context window and capabilities for Gemini 3.1 Pro Preview and GPT-5.5, side by side. Prices are the cheapest listed serving route per 1M tokens, from LiteLLM and OpenRouter.
Verdict
computed from the published numbersGemini 3.1 Pro Preview wins on price. GPT-5.5 wins on Terminal-Bench, on intelligence and on context window.
Price
Gemini 3.1 Pro Preview
Terminal-Bench
GPT-5.5
Intelligence
GPT-5.5
Context window
GPT-5.5
Key takeaways
who wins on what, from the published numbersGemini 3.1 Pro Preview wins
- Cheaper input ($2.00 vs $5.00 /1M)
- Cheaper output ($12.00 vs $30.00 /1M)
- Supports audio
GPT-5.5 wins
- Larger context window (1M vs 1.1M)
- Higher max output (66K vs 128K)
Cheaper overall
Gemini 3.1 Pro Preview
$2.00 + $12.00 /1M
Larger context
GPT-5.5
1.1M
More providers
Tied
Pricing & specs
cheapest listed route · per 1M tokensOn-demand listed rates, OpenRouter routed quotes and Vercel reseller quotes. Enterprise commitments can be materially lower.
| Gemini 3.1 Pro Preview | GPT-5.5 | |
|---|---|---|
| Input $/1M | $2.00via Google best | $5.00via OpenAI |
| Output $/1M | $12.00via Google best | $30.00via OpenAI |
| Context window | 1M | 1.1M best |
| Max output | 66K | 128K best |
| Serving providers | 6 | 6 |
| Date | Released Feb 19, 2026 | Released Apr 23, 2026 |
Benchmarks
Benchmark scores, side by side| Gemini 3.1 Pro Preview | GPT-5.5 | |
|---|---|---|
| Intelligence | 29.7 | 38.4 best |
| Terminal-Bench | 74% | 84% best |
| GPQA Diamond | 94% | 94% |
| Output speed | 140 t/s best | 102 t/s |
| Latency (TTFT) | 26.52s best | 70.60s |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Gemini 3.1 Pro Preview
via Google
$22
GPT-5.5
via OpenAI
$55
Capabilities
feature support, side by side| Feature | Gemini 3.1 Pro Preview | GPT-5.5 |
|---|---|---|
| Vision | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | ✓ | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | ✓ | ✓ |
Related comparisons
Frequently asked questions
Which is cheaper, Gemini 3.1 Pro Preview or GPT-5.5?
Gemini 3.1 Pro Preview is cheaper for input ($2.00 vs $5.00 per 1M tokens) from Google. Gemini 3.1 Pro Preview is cheaper for output ($12.00 vs $30.00 per 1M tokens) from Google.
What is the context window difference between Gemini 3.1 Pro Preview and GPT-5.5?
Gemini 3.1 Pro Preview has a 1M-token context window and GPT-5.5 has 1.1M tokens, so GPT-5.5 can take a larger prompt.
How do Gemini 3.1 Pro Preview and GPT-5.5 compare on benchmarks?
On the tracked benchmarks, GPT-5.5 leads on Terminal-Bench, and GPT-5.5 leads on intelligence.
Listed prices from LiteLLM, OpenRouter and Vercel · last checked Oct 14, 2026
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