Model Comparison
GPT-5.5 (xhigh)
vs. Gemini 3.5 Flash (high)
Comparing 2 AI models · 7 benchmarks · OpenAI, Google
Recommended Pick
Go Gemini 3.5 Flash (high) 9 metric wins Strongest on: Value, Input price, Output price
Best Value
Gemini 3.5 Flash (high)
100.0 value score
62.8 reasoning / $3.38/1M
Lowest Price
Gemini 3.5 Flash (high)
$1.50/1M input price
Best Reasoning
GPT-5.5 (xhigh)
66.0 reasoning score
Blends available reasoning benchmarks
Best for Coding
GPT-5.5 (xhigh)
59.1 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 3.5 Flash (high) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
Gemini 3.5 Flash (high) is 3.3x cheaper on input tokens than GPT-5.5 (xhigh).
Speed gap
Gemini 3.5 Flash (high) generates about 2.9x as many tokens per second as GPT-5.5 (xhigh).
Reasoning gap
GPT-5.5 (xhigh) leads Gemini 3.5 Flash (high) by 3.2 points on reasoning.
Coding gap
GPT-5.5 (xhigh) leads Gemini 3.5 Flash (high) by 14.1 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GPT-5.5 (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 3.5 Flash (high)
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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Which answer was more useful?
Full Comparison
| Metric | Op GPT-5.5 (xhigh) | Top Pick Go Gemini 3.5 Flash (high) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $5.00/1M | $1.50/1M |
| Output Cost | $30.00/1M | $9.00/1M |
| Blended (3:1) | $11.25/1M | $3.38/1M |
| Specifications | ||
| Organization | OpenAI | |
| Release Date | Apr 23, 2026 | May 19, 2026 |
| Performance & Speed | ||
| Throughput | 66.5 tok/s | 195.5 tok/s |
| TTFT | 37889ms | 11943ms |
| Latency | 37889ms | 11943ms |
| Composite Indices | ||
| Value Score | 31.5 | 100.0 |
| Reasoning Score | 66.0 | 62.8 |
| Intelligence | 60.2 | 55.3 |
| Coding | 59.1 | 45.0 |
| Standard Benchmarks | ||
| GPQA | 93.5% | 92.2% |
| HLE | 44.3% | 41.0% |
| SciCode | 56.1% | 53.1% |
| LCR | 74.3% | 69.3% |
| IFBench | 75.9% | 76.3% |
| TAU-bench v2 | 93.9% | 95.3% |
| TerminalBench Hard | 60.6% | 40.9% |
Key Takeaways
Gemini 3.5 Flash (high) offers the best value at $1.50/1M, making it ideal for high-volume applications and cost-conscious projects.
GPT-5.5 (xhigh) has the strongest reasoning profile with a 66.0 reasoning score, combining the available reasoning-heavy benchmarks.
GPT-5.5 (xhigh) reaches a 59.1 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-5.5 (xhigh)
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
Gemini 3.5 Flash (high)
- Cost-sensitive applications
- High-volume processing
