Model Comparison
GPT-5 Codex (high)
vs. Gemini 3.1 Pro Preview
Comparing 2 AI models · 10 benchmarks · OpenAI, Google
Recommended Pick
Go Gemini 3.1 Pro Preview 9 metric wins Strongest on: Intelligence, Coding, GPQA
Best Value
GPT-5 Codex (high)
100.0 value score
70.3 reasoning / $3.44/1M
Lowest Price
GPT-5 Codex (high)
$1.25/1M input price
Best Reasoning
GPT-5 Codex (high)
70.3 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 Codex (high) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GPT-5 Codex (high) is 1.6x cheaper on input tokens than Gemini 3.1 Pro Preview.
Speed gap
GPT-5 Codex (high) generates about 1.5x as many tokens per second as Gemini 3.1 Pro Preview.
Reasoning gap
GPT-5 Codex (high) leads Gemini 3.1 Pro Preview by 4.9 points on reasoning.
Coding gap
Gemini 3.1 Pro Preview leads GPT-5 Codex (high) by 16.6 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 Codex (high)
OpenAI
TTFT
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Time
—
tok/s
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Tokens
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Cost
—
Gemini 3.1 Pro Preview
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
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Which answer was more useful?
Full Comparison
| Metric | Op GPT-5 Codex (high) | Top Pick Go Gemini 3.1 Pro Preview |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $1.25/1M | $2.00/1M |
| Output Cost | $10.00/1M | $12.00/1M |
| Blended (3:1) | $3.44/1M | $4.50/1M |
| Specifications | ||
| Organization | OpenAI | |
| Release Date | Sep 23, 2025 | Feb 19, 2026 |
| Performance & Speed | ||
| Throughput | 197.0 tok/s | 133.5 tok/s |
| TTFT | 8040ms | 33152ms |
| Latency | 8040ms | 33152ms |
| Composite Indices | ||
| Value Score | 100.0 | 71.0 |
| Reasoning Score | 70.3 | 65.3 |
| Intelligence | 44.6 | 57.2 |
| Coding | 38.9 | 55.5 |
| Math | 98.7 | — |
| Standard Benchmarks | ||
| GPQA | 83.7% | 94.1% |
| MMLU Pro | 86.5% | — |
| HLE | 25.6% | 44.7% |
| LiveCodeBench | 84.0% | — |
| AIME 2025 | 98.7% | — |
| SciCode | 40.9% | 58.9% |
| LCR | 69.0% | 72.7% |
| IFBench | 74.1% | 77.1% |
| TAU-bench v2 | 86.8% | 95.6% |
| TerminalBench Hard | 37.9% | 53.8% |
Key Takeaways
GPT-5 Codex (high) offers the best value at $1.25/1M, making it ideal for high-volume applications and cost-conscious projects.
GPT-5 Codex (high) has the strongest reasoning profile with a 70.3 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 Codex (high)
- Cost-sensitive applications
- High-volume processing
- Complex reasoning tasks
- Research & analysis
Gemini 3.1 Pro Preview
- Code generation
- Software development
