Model Comparison
GPT-5.4 nano (medium)
vs. GPT-5.5 Pro (xhigh)
Comparing 2 AI models · 7 benchmarks · OpenAI
Recommended Pick
Op GPT-5.5 Pro (xhigh) 4 metric wins Strongest on: Input price, Output price, TTFT
Lowest Price
GPT-5.5 Pro (xhigh)
$0.00/1M input price
Best for Coding
GPT-5.4 nano (medium)
35.0 coding index
Composite Indices
Higher is better; speed and price are normalized
Standard Benchmarks
Only benchmarks with data are shown
Differences That Matter
Price gap
GPT-5.5 Pro (xhigh) is ∞x cheaper on input tokens than GPT-5.4 nano (medium).
Top-pick rationale
GPT-5.5 Pro (xhigh) wins 4 measurable categories, including Input price, Output price, TTFT, Latency.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GPT-5.4 nano (medium)
OpenAI
TTFT
—
Time
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tok/s
—
Tokens
—
Cost
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GPT-5.5 Pro (xhigh)
OpenAI
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
Full Comparison
| Metric | Op GPT-5.4 nano (medium) | Top Pick Op GPT-5.5 Pro (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.20/1M | $0.00/1M |
| Output Cost | $1.25/1M | $0.00/1M |
| Blended (3:1) | $0.46/1M | — |
| Specifications | ||
| Organization | OpenAI | OpenAI |
| Release Date | Mar 17, 2026 | Apr 23, 2026 |
| Performance & Speed | ||
| Throughput | 161.4 tok/s | — |
| TTFT | 3858ms | — |
| Latency | 3858ms | — |
| Composite Indices | ||
| Value Score | 100.0 | — |
| Reasoning Score | 43.0 | — |
| Intelligence | 38.1 | — |
| Coding | 35.0 | — |
| Standard Benchmarks | ||
| GPQA | 76.1% | — |
| HLE | 14.7% | — |
| SciCode | 38.4% | — |
| LCR | 57.3% | — |
| IFBench | 64.4% | — |
| TAU-bench v2 | 52.6% | — |
| TerminalBench Hard | 33.3% | — |
Key Takeaways
GPT-5.5 Pro (xhigh) offers the best value at $0.00/1M, making it ideal for high-volume applications and cost-conscious projects.
GPT-5.4 nano (medium) reaches a 35.0 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-5.4 nano (medium)
- Code generation
- Software development
GPT-5.5 Pro (xhigh)
- Cost-sensitive applications
- High-volume processing
