OpenAI: gpt-oss-120b vs Google: Gemini 3.1 Pro Preview Custom Tools: Which AI Model Is Better?
Updated March 24, 2026· Based on independent benchmark data
Quick Verdict
Google: Gemini 3.1 Pro Preview Custom Tools leads in intelligence with a score of 57.2 vs 33.3. OpenAI: gpt-oss-120b is 51.3x cheaper at $0.04/1M tokens vs $2.00/1M. For speed, OpenAI: gpt-oss-120b wins at 289 tok/s vs 117 tok/s.
Head-to-Head Comparison
| Metric | OpenAI: gpt-oss-120b | Google: Gemini 3.1 Pro Preview Custom Tools |
|---|---|---|
| Intelligence Score | 33.3 | 57.2 |
| Coding Score | 28.6 | 55.5 |
| Math Score | 93.4 | N/A |
| Speed (tok/s) | 289 tok/s | 117 tok/s |
| Latency (TTFT) | 0.49s | 21.91s |
| Input Price / 1M tokens | $0.04 | $2.00 |
| Output Price / 1M tokens | $0.19 | $12 |
| Context Window | 131K | 1.0M |
| Max Output Tokens | N/A | 66K |
| Input Modalities | Text | Text + Audio + Image + Video + File |
| Output Modalities | Text | Text |
| Free Tier | No | No |
Detailed Analysis
Intelligence & Quality
Google: Gemini 3.1 Pro Preview Custom Tools outperforms OpenAI: gpt-oss-120b on the Artificial Analysis intelligence index with a score of 57.2 compared to 33.3. For coding tasks, Google: Gemini 3.1 Pro Preview Custom Tools has the edge with a coding score of 55.5 vs 28.6.
Speed & Latency
OpenAI: gpt-oss-120b generates output significantly faster at 289 tok/s compared to Google: Gemini 3.1 Pro Preview Custom Tools's 117 tok/s, making it 2.5x faster for streaming responses. Time to first token is 0.49s for OpenAI: gpt-oss-120b vs 21.91s for Google: Gemini 3.1 Pro Preview Custom Tools, which affects perceived responsiveness in interactive applications.
Pricing
OpenAI: gpt-oss-120b is more affordable at $0.04/1M input tokens ($0.19/1M output), while Google: Gemini 3.1 Pro Preview Custom Tools costs $2.00/1M input ($12/1M output). That makes Google: Gemini 3.1 Pro Preview Custom Tools 51.3x more expensive per token, which can add up significantly at scale. For a typical workload of 100 requests per day at 2,000 tokens each, OpenAI: gpt-oss-120b would cost approximately $0.23/month vs $12.00/month for Google: Gemini 3.1 Pro Preview Custom Tools in input costs alone.
Context Window
Google: Gemini 3.1 Pro Preview Custom Tools offers a larger context window at 1.0M tokens compared to OpenAI: gpt-oss-120b's 131K. This means Google: Gemini 3.1 Pro Preview Custom Tools can process roughly 524 pages of text in a single request vs 66 pages for OpenAI: gpt-oss-120b.
Best Use Cases
Choose OpenAI: gpt-oss-120b when you need faster output (289 tok/s), lower cost. Choose Google: Gemini 3.1 Pro Preview Custom Tools when you need higher intelligence (57.2), stronger coding performance (55.5), larger context window (1.0M).
Choose OpenAI: gpt-oss-120b if:
- ✓You need faster throughput (289 tok/s vs 117 tok/s)
- ✓You want lower latency (0.49s vs 21.91s TTFT)
- ✓Budget is a concern ($0.04/1M vs $2.00/1M)
Choose Google: Gemini 3.1 Pro Preview Custom Tools if:
- ✓You need higher intelligence (score: 57.2 vs 33.3)
- ✓You prioritize coding performance (score: 55.5 vs 28.6)
- ✓You need a larger context window (1.0M vs 131K)
- ✓You need image understanding (Supports image input)
Frequently Asked Questions
Is OpenAI: gpt-oss-120b better than Google: Gemini 3.1 Pro Preview Custom Tools for coding?
Google: Gemini 3.1 Pro Preview Custom Tools scores higher on coding benchmarks (55.5 vs 28.6), making it the better choice for programming tasks.
Which is cheaper, OpenAI: gpt-oss-120b or Google: Gemini 3.1 Pro Preview Custom Tools?
OpenAI: gpt-oss-120b is cheaper at $0.04/1M input tokens vs $2.00/1M for Google: Gemini 3.1 Pro Preview Custom Tools.
Is OpenAI: gpt-oss-120b faster than Google: Gemini 3.1 Pro Preview Custom Tools?
OpenAI: gpt-oss-120b is faster, producing output at 289 tok/s compared to Google: Gemini 3.1 Pro Preview Custom Tools's 117 tok/s.
Can OpenAI: gpt-oss-120b process images?
No, OpenAI: gpt-oss-120b does not support image input. However, Google: Gemini 3.1 Pro Preview Custom Tools does support images.
Which has a larger context window, OpenAI: gpt-oss-120b or Google: Gemini 3.1 Pro Preview Custom Tools?
Google: Gemini 3.1 Pro Preview Custom Tools has a larger context window at 1.0M compared to OpenAI: gpt-oss-120b's 131K.
Should I use OpenAI: gpt-oss-120b or Google: Gemini 3.1 Pro Preview Custom Tools?
It depends on your priorities. Google: Gemini 3.1 Pro Preview Custom Tools scores higher on intelligence (57.2), but OpenAI: gpt-oss-120b may be better for specific use cases like budget-conscious projects or speed-critical applications.
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Benchmark data by Artificial Analysis
Data last synced: March 24, 2026