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Model Comparison

Kimi K2.5 vs GPT-5.5 Pro

GPT-5.5 Pro significantly outperforms across most benchmarks. Kimi K2.5 is 56.3x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Kimi K2.5 outperforms in 0 benchmarks, while GPT-5.5 Pro is better at 2 benchmarks (BrowseComp, Humanity's Last Exam).

GPT-5.5 Pro significantly outperforms across most benchmarks.

Thu Apr 23 2026 • llm-stats.com

Arena Performance

Human preference votes

CallingBox

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$0.05 /min all-in7 lines of code

Pricing Analysis

Price comparison per million tokens

Kimi K2.5 costs less

For input processing, Kimi K2.5 ($0.60/1M tokens) is 50.0x cheaper than GPT-5.5 Pro ($30.00/1M tokens).

For output processing, Kimi K2.5 ($3.00/1M tokens) is 60.0x cheaper than GPT-5.5 Pro ($180.00/1M tokens).

In conclusion, GPT-5.5 Pro is more expensive than Kimi K2.5.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Apr 23 2026 • llm-stats.com
Moonshot AI
Kimi K2.5
Input tokens$0.60
Output tokens$3.00
Best providerFireworks
OpenAI
GPT-5.5 Pro
Input tokens$30.00
Output tokens$180.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 Pro accepts 1,000,000 input tokens compared to Kimi K2.5's 262,100 tokens. Kimi K2.5 can generate longer responses up to 262,100 tokens, while GPT-5.5 Pro is limited to 128,000 tokens.

Moonshot AI
Kimi K2.5
Input262,100 tokens
Output262,100 tokens
OpenAI
GPT-5.5 Pro
Input1,000,000 tokens
Output128,000 tokens
Thu Apr 23 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Kimi K2.5 and GPT-5.5 Pro support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Kimi K2.5

Text
Images
Audio
Video

GPT-5.5 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

Kimi K2.5 is licensed under MIT, while GPT-5.5 Pro uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

Kimi K2.5

MIT

Open weights

GPT-5.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Kimi K2.5 was released on 2026-01-27, while GPT-5.5 Pro was released on 2026-04-23.

GPT-5.5 Pro is 3 months newer than Kimi K2.5.

Kimi K2.5

Jan 27, 2026

2 months ago

GPT-5.5 Pro

Apr 23, 2026

0 days ago

2mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Kimi K2.5 is available from Fireworks, Moonshot AI. GPT-5.5 Pro is available from OpenAI.

Kimi K2.5

fireworks logo
Fireworks
Input Price:Input: $0.60/1MOutput Price:Output: $3.00/1M
moonshot logo
Unknown Organization
Input Price:Input: $0.60/1MOutput Price:Output: $3.00/1M

GPT-5.5 Pro

openai logo
OpenAI
Input Price:Input: $30.00/1MOutput Price:Output: $180.00/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Moonshot AI
Less expensive input tokens
Less expensive output tokens
Has open weights
OpenAI
Larger context window (1,000,000 tokens)
Higher BrowseComp score (90.1% vs 74.9%)
Higher Humanity's Last Exam score (57.2% vs 50.2%)

Detailed Comparison

AI Model Comparison Table
Feature
Moonshot AI
Kimi K2.5
OpenAI
GPT-5.5 Pro

FAQ

Common questions about Kimi K2.5 vs GPT-5.5 Pro

GPT-5.5 Pro significantly outperforms across most benchmarks. Kimi K2.5 is made by Moonshot AI and GPT-5.5 Pro is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Kimi K2.5 scores AIME 2025: 96.1%, HMMT 2025: 95.4%, InfoVQAtest: 92.6%, OCRBench: 92.3%, MathVista-Mini: 90.1%. GPT-5.5 Pro scores BrowseComp: 90.1%, GDPval-MM: 82.3%, Humanity's Last Exam: 57.2%, FrontierMath: 39.6%, GeneBench: 33.2%.
Kimi K2.5 is 50.0x cheaper for input tokens. Kimi K2.5 costs $0.60/M input and $3.00/M output via fireworks. GPT-5.5 Pro costs $30.00/M input and $180.00/M output via openai.
Kimi K2.5 supports 262K tokens and GPT-5.5 Pro supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (262K vs 1.0M), input pricing ($0.60 vs $30.00/M), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.
Kimi K2.5 is developed by Moonshot AI and GPT-5.5 Pro is developed by OpenAI.