Model Comparison
Grok-4.20 Beta Reasoning vs Kimi K3Which is better in 2026?
Comparing Grok-4.20 Beta Reasoning and Kimi K3 across benchmarks, pricing, and capabilities.
Verdict: Grok-4.20 Beta Reasoning vs Kimi K3 — which is better?
Grok-4.20 Beta Reasoning (by xAI) and Kimi K3 (by Moonshot AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
On price, Grok-4.20 Beta Reasoning is roughly 2.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4.20 Beta Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose Grok-4.20 Beta Reasoning if…
- cost matters — it's about 2.0x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
Choose Kimi K3 if…
- you want the most recent training data — it shipped Jul 2026
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
Grok-4.20 Beta Reasoning and Kimi K3don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Grok-4.20 Beta Reasoning ($2.00/1M tokens) is 1.5x cheaper than Kimi K3 ($3.00/1M tokens).
For output processing, Grok-4.20 Beta Reasoning ($6.00/1M tokens) is 2.5x cheaper than Kimi K3 ($15.00/1M tokens).
In conclusion, Kimi K3 is more expensive than Grok-4.20 Beta Reasoning.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4.20 Beta Reasoning accepts 2,000,000 input tokens compared to Kimi K3's 1,048,576 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while Grok-4.20 Beta Reasoning is limited to 30,000 tokens.
Input Capabilities
Supported data types and modalities
Both Grok-4.20 Beta Reasoning and Kimi K3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Grok-4.20 Beta Reasoning
Kimi K3
License
Usage and distribution terms
Grok-4.20 Beta Reasoning is licensed under a proprietary license, while Kimi K3 uses Kimi K3 License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Kimi K3 License
Open weights
Release Timeline
When each model was launched
Grok-4.20 Beta Reasoning was released on 2026-03-09, while Kimi K3 was released on 2026-07-16.
Kimi K3 is 4 months newer than Grok-4.20 Beta Reasoning.
Mar 9, 2026
4 months ago
Jul 16, 2026
1 weeks ago
4mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Grok-4.20 Beta Reasoning is available from xAI. Kimi K3 is available from Fireworks, Moonshot AI, Novita, Together.
Grok-4.20 Beta Reasoning
Kimi K3
Outputs Comparison
Key Takeaways
Kimi K3
View detailsMoonshot AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Grok-4.20 Beta Reasoning and Kimi K3 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Grok-4.20 Beta Reasoning vs Kimi K3.