Model Comparison
GPT-5.3 Codex (xhigh)
vs. Gemini 3.1 Pro Preview
Comparing 2 AI models · 7 benchmarks · OpenAI, Google
Recommended Pick
Go Gemini 3.1 Pro Preview 15 metric wins Strongest on: Value, Output price, Blended price
Best Value
Gemini 3.1 Pro Preview
100.0 value score
65.3 reasoning / $4.50/1M
Lowest Price
GPT-5.3 Codex (xhigh)
$1.75/1M 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
Gemini 3.1 Pro Preview has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GPT-5.3 Codex (xhigh) is 1.1x cheaper on input tokens than Gemini 3.1 Pro Preview.
Speed gap
Gemini 3.1 Pro Preview generates about 1.7x as many tokens per second as GPT-5.3 Codex (xhigh).
Reasoning gap
Gemini 3.1 Pro Preview leads GPT-5.3 Codex (xhigh) by 3.7 points on reasoning.
Coding gap
Gemini 3.1 Pro Preview leads GPT-5.3 Codex (xhigh) by 2.4 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GPT-5.3 Codex (xhigh)
OpenAI
TTFT
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Time
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tok/s
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Tokens
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Cost
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Gemini 3.1 Pro Preview
TTFT
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Time
—
tok/s
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Tokens
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Cost
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Which answer was more useful?
Full Comparison
| Metric | Op GPT-5.3 Codex (xhigh) | Top Pick Go Gemini 3.1 Pro Preview |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $1.75/1M | $2.00/1M |
| Output Cost | $14.00/1M | $12.00/1M |
| Blended (3:1) | $4.81/1M | $4.50/1M |
| Specifications | ||
| Organization | OpenAI | |
| Release Date | Feb 5, 2026 | Feb 19, 2026 |
| Performance & Speed | ||
| Throughput | 70.8 tok/s | 117.7 tok/s |
| TTFT | 67373ms | 21280ms |
| Latency | 67373ms | 21280ms |
| Composite Indices | ||
| Value Score | 88.3 | 100.0 |
| Reasoning Score | 61.7 | 65.3 |
| Intelligence | 53.6 | 57.2 |
| Coding | 53.1 | 55.5 |
| Standard Benchmarks | ||
| GPQA | 91.5% | 94.1% |
| HLE | 39.9% | 44.7% |
| SciCode | 53.2% | 58.9% |
| LCR | 74.0% | 72.7% |
| IFBench | 75.4% | 77.1% |
| TAU-bench v2 | 86.0% | 95.6% |
| TerminalBench Hard | 53.0% | 53.8% |
Key Takeaways
GPT-5.3 Codex (xhigh) offers the best value at $1.75/1M, 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-5.3 Codex (xhigh)
- Cost-sensitive applications
- High-volume processing
Gemini 3.1 Pro Preview
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
