KimivsMoonshot Kimi k2
Moonshot AI vs Moonshot AI — Side-by-side model comparison
Head-to-Head Comparison
| Metric | Kimi | Moonshot Kimi k2 |
|---|---|---|
| Provider | Moonshot AI | |
| Arena Rank | — | #8 |
| Context Window | 2M | 131K |
| Input Pricing | Undisclosed/1M tokens | $0.55/1M tokens |
| Output Pricing | Undisclosed/1M tokens | $2.20/1M tokens |
| Parameters | Undisclosed | 1T MoE |
| Open Source | No | Yes |
| Best For | Ultra-long documents, research, analysis | Coding, agentic tasks, reasoning |
| Release Date | Mar 18, 2024 | Jul 1, 2025 |
Kimi
Kimi is Moonshot AI's flagship model featuring an industry-leading 2 million token context window, the largest publicly available at launch. This extraordinary context length enables processing of entire books, research paper collections, and massive codebases in a single prompt. Developed by a team of former Google and Microsoft researchers in Beijing, Kimi has become one of China's most popular AI assistants, particularly valued for its ability to analyze very long documents.
View Moonshot AI profile →Moonshot Kimi k2
Moonshot Kimi k2 is a massive open-source model with 1 trillion mixture-of-experts parameters, making it one of the largest openly available AI models. Developed by Chinese AI startup Moonshot AI (creators of the popular Kimi chatbot), it rivals frontier proprietary models on coding and agentic benchmarks while being freely accessible. The model uses an efficient MoE architecture where only a fraction of parameters activate per token, keeping inference costs manageable despite its enormous size. Kimi k2 excels at code generation, tool use, and multi-step reasoning tasks. Its release represents a significant milestone in open-source AI, demonstrating that the community can produce models competitive with the largest proprietary systems.
Key Differences: Kimi vs Moonshot Kimi k2
Kimi supports a larger context window (2M), allowing it to process longer documents in a single request.
Moonshot Kimi k2 is open-source (free to self-host and fine-tune) while Kimi is proprietary (API-only access).
When to use Kimi
- +You need to process long documents (2M context)
- +You prefer a managed API without infrastructure overhead
- +Your use case involves ultra-long documents, research, analysis
When to use Moonshot Kimi k2
- +You need to self-host or fine-tune the model
- +Your use case involves coding, agentic tasks, reasoning
The Verdict
Moonshot Kimi k2 wins our head-to-head comparison with 4 out of 5 category wins. It's the stronger choice for coding, agentic tasks, reasoning, though Kimi holds an edge in ultra-long documents, research, analysis.
Last compared: March 2026 · Data sourced from public benchmarks and official pricing pages