Model Comparison
GPT-5.1 Codex mini (high)
vs. Gemini 3.1 Pro Preview
Comparing 2 AI models · 10 benchmarks · OpenAI, Google
Recommended Pick
Go Gemini 3.1 Pro Preview 10 metric wins Strongest on: Reasoning, Intelligence, Coding
Best Value
GPT-5.1 Codex mini (high)
100.0 value score
64.0 reasoning / $0.69/1M
Lowest Price
GPT-5.1 Codex mini (high)
$0.25/1M input price
Best Reasoning
Gemini 3.1 Pro Preview
65.3 reasoning score
Blends available reasoning benchmarks
Best for Coding
Gemini 3.1 Pro Preview
55.5 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Best value
GPT-5.1 Codex mini (high) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GPT-5.1 Codex mini (high) is 8.0x cheaper on input tokens than Gemini 3.1 Pro Preview.
Speed gap
GPT-5.1 Codex mini (high) generates about 1.6x as many tokens per second as Gemini 3.1 Pro Preview.
Reasoning gap
Gemini 3.1 Pro Preview leads GPT-5.1 Codex mini (high) by 1.3 points on reasoning.
Coding gap
Gemini 3.1 Pro Preview leads GPT-5.1 Codex mini (high) by 19.1 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GPT-5.1 Codex mini (high)
OpenAI
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Gemini 3.1 Pro Preview
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
Full Comparison
| Metric | Op GPT-5.1 Codex mini (high) | Top Pick Go Gemini 3.1 Pro Preview |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.25/1M | $2.00/1M |
| Output Cost | $2.00/1M | $12.00/1M |
| Blended (3:1) | $0.69/1M | $4.50/1M |
| Specifications | ||
| Organization | OpenAI | |
| Release Date | Nov 13, 2025 | Feb 19, 2026 |
| Performance & Speed | ||
| Throughput | 218.4 tok/s | 135.9 tok/s |
| TTFT | 4447ms | 28145ms |
| Latency | 4447ms | 28145ms |
| Composite Indices | ||
| Value Score | 100.0 | 15.6 |
| Reasoning Score | 64.0 | 65.3 |
| Intelligence | 38.6 | 57.2 |
| Coding | 36.4 | 55.5 |
| Math | 91.7 | — |
| Standard Benchmarks | ||
| GPQA | 81.3% | 94.1% |
| MMLU Pro | 82.0% | — |
| HLE | 16.9% | 44.7% |
| LiveCodeBench | 83.6% | — |
| AIME 2025 | 91.7% | — |
| SciCode | 42.6% | 58.9% |
| LCR | 62.7% | 72.7% |
| IFBench | 67.9% | 77.1% |
| TAU-bench v2 | 62.9% | 95.6% |
| TerminalBench Hard | 33.3% | 53.8% |
Key Takeaways
GPT-5.1 Codex mini (high) offers the best value at $0.25/1M, making it ideal for high-volume applications and cost-conscious projects.
Gemini 3.1 Pro Preview has the strongest reasoning profile with a 65.3 reasoning score, combining the available reasoning-heavy benchmarks.
Gemini 3.1 Pro Preview reaches a 55.5 coding index, making it the top choice for software development and code generation tasks.
All models support context windows of ∞+ tokens, suitable for processing lengthy documents and maintaining extended conversations.
When to Choose Each Model
GPT-5.1 Codex mini (high)
- Cost-sensitive applications
- High-volume processing
Gemini 3.1 Pro Preview
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
