Model Comparison
GLM-4.5 (Reasoning)
vs. GPT-5.5 (xhigh)
Comparing 2 AI models · 12 benchmarks · Z AI, OpenAI
Recommended Pick
Op GPT-5.5 (xhigh) 12 metric wins Strongest on: Throughput, Latency, Reasoning
Best Value
GLM-4.5 (Reasoning)
100.0 value score
64.2 reasoning / $1.00/1M
Lowest Price
GLM-4.5 (Reasoning)
$0.60/1M 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
GLM-4.5 (Reasoning) has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
GLM-4.5 (Reasoning) is 8.3x cheaper on input tokens than GPT-5.5 (xhigh).
Speed gap
GPT-5.5 (xhigh) generates about 1.3x as many tokens per second as GLM-4.5 (Reasoning).
Reasoning gap
GPT-5.5 (xhigh) leads GLM-4.5 (Reasoning) by 1.8 points on reasoning.
Coding gap
GPT-5.5 (xhigh) leads GLM-4.5 (Reasoning) by 32.8 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
GLM-4.5 (Reasoning)
Z AI
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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GPT-5.5 (xhigh)
OpenAI
TTFT
—
Time
—
tok/s
—
Tokens
—
Cost
—
Which answer was more useful?
Full Comparison
| Metric | Z GLM-4.5 (Reasoning) | Top Pick Op GPT-5.5 (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.60/1M | $5.00/1M |
| Output Cost | $2.20/1M | $30.00/1M |
| Blended (3:1) | $1.00/1M | $11.25/1M |
| Specifications | ||
| Organization | Z AI | OpenAI |
| Release Date | Jul 28, 2025 | Apr 23, 2026 |
| Performance & Speed | ||
| Throughput | 50.1 tok/s | 66.5 tok/s |
| TTFT | 1306ms | 37889ms |
| Latency | 41261ms | 37889ms |
| Composite Indices | ||
| Value Score | 100.0 | 9.1 |
| Reasoning Score | 64.2 | 66.0 |
| Intelligence | 26.4 | 60.2 |
| Coding | 26.3 | 59.1 |
| Math | 73.7 | — |
| Standard Benchmarks | ||
| GPQA | 78.2% | 93.5% |
| MMLU Pro | 83.5% | — |
| HLE | 12.2% | 44.3% |
| LiveCodeBench | 73.8% | — |
| MATH 500 | 97.9% | — |
| AIME 2025 | 73.7% | — |
| AIME (Original) | 87.3% | — |
| SciCode | 34.8% | 56.1% |
| LCR | 48.3% | 74.3% |
| IFBench | 44.1% | 75.9% |
| TAU-bench v2 | 43.0% | 93.9% |
| TerminalBench Hard | 22.0% | 60.6% |
Key Takeaways
GLM-4.5 (Reasoning) offers the best value at $0.60/1M, 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
GLM-4.5 (Reasoning)
- Cost-sensitive applications
- High-volume processing
GPT-5.5 (xhigh)
- Complex reasoning tasks
- Research & analysis
- Code generation
- Software development
