Model Comparison

Grok 4.5 vs Kimi K2 0905Which is better in 2026?

Grok 4.5 significantly outperforms across most benchmarks. Kimi K2 0905 is 2.8x cheaper per token.

Verdict: Grok 4.5 vs Kimi K2 0905 — which is better?

Grok 4.5 (by xAI) and Kimi K2 0905 (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.

Grok 4.5 outperforms in 1 benchmarks (GPQA), while Kimi K2 0905 is better at 0 benchmarks. Grok 4.5 significantly outperforms across most benchmarks.

On price, Kimi K2 0905 is roughly 2.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Grok 4.5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you process long inputs — it offers a 500,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose Kimi K2 0905 if…

  • cost matters — it's about 2.8x cheaper per token

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok 4.5 outperforms in 1 benchmarks (GPQA), while Kimi K2 0905 is better at 0 benchmarks.

Grok 4.5 significantly outperforms across most benchmarks.

Wed Jul 22 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Kimi K2 0905 costs less

For input processing, Grok 4.5 ($2.00/1M tokens) is 3.3x more expensive than Kimi K2 0905 ($0.60/1M tokens).

For output processing, Grok 4.5 ($6.00/1M tokens) is 2.4x more expensive than Kimi K2 0905 ($2.50/1M tokens).

In conclusion, Grok 4.5 is more expensive than Kimi K2 0905.*

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

Lowest available price from all providers
Wed Jul 22 2026 • llm-stats.com
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Moonshot AI
Kimi K2 0905
Input tokens$0.60
Output tokens$2.50
Best providerNovita
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4.5 accepts 500,000 input tokens compared to Kimi K2 0905's 262,144 tokens. Only Kimi K2 0905 specifies output context (262,144 tokens).

xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Moonshot AI
Kimi K2 0905
Input262,144 tokens
Output262,144 tokens
Wed Jul 22 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok 4.5 supports multimodal inputs, whereas Kimi K2 0905 does not.

Grok 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok 4.5

Text
Images
Audio
Video

Kimi K2 0905

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Grok 4.5

Proprietary

Closed source

Kimi K2 0905

Proprietary

Closed source

Release Timeline

When each model was launched

Grok 4.5 was released on 2026-07-16, while Kimi K2 0905 was released on 2025-09-05.

Grok 4.5 is 10 months newer than Kimi K2 0905.

Grok 4.5

Jul 16, 2026

6 days ago

10mo newer
Kimi K2 0905

Sep 5, 2025

10 months ago

Knowledge Cutoff

When training data ends

Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Kimi K2 0905's cutoff date is not specified.

We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without Kimi K2 0905's cutoff date.

Grok 4.5

Feb 2026

Kimi K2 0905

—

Provider Availability

Grok 4.5 is available from xAI. Kimi K2 0905 is available from Novita.

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M

Kimi K2 0905

novita logo
Novita
Input Price:Input: $0.60/1MOutput Price:Output: $2.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Larger context window (500,000 tokens)
Supports multimodal inputs
Higher GPQA score (93.0% vs 75.8%)
Moonshot AI
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok 4.5 and Kimi K2 0905 side-by-side, then vote on the output you prefer.

Grok 4.5
✓ Preferred
Kimi K2 0905
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok 4.5
Moonshot AI
Kimi K2 0905

FAQ

Common questions about Grok 4.5 vs Kimi K2 0905.

Which is better, Grok 4.5 or Kimi K2 0905?

Grok 4.5 significantly outperforms across most benchmarks. Grok 4.5 is made by xAI and Kimi K2 0905 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok 4.5 compare to Kimi K2 0905 in benchmarks?

Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, Artificial Analysis Coding Agent Index v1.1: 76.0%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%. Kimi K2 0905 scores HumanEval: 94.5%, MMLU: 90.2%, MATH: 89.1%, MMLU-Pro: 82.5%, GPQA: 75.8%.

Is Grok 4.5 cheaper than Kimi K2 0905?

Kimi K2 0905 is 3.3x cheaper for input tokens. Grok 4.5 costs $2.00/M input and $6.00/M output via xai. Kimi K2 0905 costs $0.60/M input and $2.50/M output via novita.

What are the context window sizes for Grok 4.5 and Kimi K2 0905?

Grok 4.5 supports 500K tokens and Kimi K2 0905 supports 262K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok 4.5 and Kimi K2 0905?

Key differences include context window (500K vs 262K), input pricing ($2.00 vs $0.60/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok 4.5 and Kimi K2 0905?

Grok 4.5 is developed by xAI and Kimi K2 0905 is developed by Moonshot AI.

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