Model Comparison
Kimi K2 Thinking
vs. GPT-5.5 (xhigh)
Comparing 2 AI models · 10 benchmarks · MoonshotAI, OpenAI
Recommended Pick
Op GPT-5.5 (xhigh) 9 metric wins Strongest on: Intelligence, Coding, GPQA
Best Value
Kimi K2 Thinking
100.0 value score
67.3 reasoning / $1.07/1M
Lowest Price
Kimi K2 Thinking
$0.60/1M input price
Best Reasoning
Kimi K2 Thinking
67.3 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
Kimi K2 Thinking has the strongest quality-to-price mix at 100.0 out of 100 value points.
Price gap
Kimi K2 Thinking is 8.3x cheaper on input tokens than GPT-5.5 (xhigh).
Speed gap
Kimi K2 Thinking generates about 2.2x as many tokens per second as GPT-5.5 (xhigh).
Reasoning gap
Kimi K2 Thinking leads GPT-5.5 (xhigh) by 1.3 points on reasoning.
Coding gap
GPT-5.5 (xhigh) leads Kimi K2 Thinking by 24.3 points on coding.
Response Face-Off
Run one prompt through the selected models and compare response quality with live speed and cost context.
Kimi K2 Thinking
MoonshotAI
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
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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 | Mo Kimi K2 Thinking | Top Pick Op GPT-5.5 (xhigh) |
|---|---|---|
| Pricing per 1M tokens | ||
| Input Cost | $0.60/1M | $5.00/1M |
| Output Cost | $2.50/1M | $30.00/1M |
| Blended (3:1) | $1.07/1M | $11.25/1M |
| Specifications | ||
| Organization | MoonshotAI | OpenAI |
| Release Date | Nov 6, 2025 | Apr 23, 2026 |
| Performance & Speed | ||
| Throughput | 128.5 tok/s | 58.6 tok/s |
| TTFT | 911ms | 70541ms |
| Latency | 16472ms | 70541ms |
| Composite Indices | ||
| Value Score | 100.0 | 9.4 |
| Reasoning Score | 67.3 | 66.0 |
| Intelligence | 40.9 | 60.2 |
| Coding | 34.8 | 59.1 |
| Math | 94.7 | — |
| Standard Benchmarks | ||
| GPQA | 83.8% | 93.5% |
| MMLU Pro | 84.8% | — |
| HLE | 22.3% | 44.3% |
| LiveCodeBench | 85.3% | — |
| AIME 2025 | 94.7% | — |
| SciCode | 42.4% | 56.1% |
| LCR | 66.3% | 74.3% |
| IFBench | 68.1% | 75.9% |
| TAU-bench v2 | 93.0% | 93.9% |
| TerminalBench Hard | 31.1% | 60.6% |
Key Takeaways
Kimi K2 Thinking offers the best value at $0.60/1M, making it ideal for high-volume applications and cost-conscious projects.
Kimi K2 Thinking has the strongest reasoning profile with a 67.3 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
Kimi K2 Thinking
- Cost-sensitive applications
- High-volume processing
- Complex reasoning tasks
- Research & analysis
GPT-5.5 (xhigh)
- Code generation
- Software development
