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Grok 4.5 vs Kimi K3

Kimi K3 leads the LLM Stats Score 53.0 to 45.4. Grok 4.5 is 1.9x cheaper per token.

xAI · Moonshot AI · Updated for 2026

Which is better?

Kimi K3 leads the overall LLM Stats Score 53.0 to 45.4, ranking #8 overall.

In the 5 individual benchmarks reported for both models, Kimi K3 wins 5; this is a narrower head-to-head signal than the composite indexes.

On price, Grok 4.5 is roughly 1.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Kimi K3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Grok 4.5

  • cost matters — it's about 1.9x cheaper per token

Choose Kimi K3

  • overall performance matters — it scores 53.0 and ranks #8 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 5 exact shared results
  • you process long inputs — it offers a 1,048,576 token context window
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
45.4
#30
53.0
#8
43.9
#38
51.6
#9
35.3
#29
43.3
#6
31.0
#32
39.2
#9
Cost, coverage & limits
Benchmark wins
0 of 5
5 of 5
Input price
$2.00 / M
$2.85 / M
Output price
$6.00 / M
$14.25 / M
Context window
500,000
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Grok 4.5
Kimi K3
21.9#49
33.8#3
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

15 reported for Grok 4.5 · 31 for Kimi K3

5 shared

Grok 4.5 outperforms in 0 benchmarks, while Kimi K3 is better at 5 benchmarks (DeepSWE, DeepSWE 1.1, GPQA, SWE-Marathon, Terminal-Bench 2.1).

Kimi K3 significantly outperforms across most benchmarks.

Mon Sep 21 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Grok 4.5 costs less

For input processing, Grok 4.5 ($2.00/1M tokens) is 1.4x cheaper than Kimi K3 ($2.85/1M tokens).

For output processing, Grok 4.5 ($6.00/1M tokens) is 2.4x cheaper than Kimi K3 ($14.25/1M tokens).

In conclusion, Kimi K3 is more expensive than Grok 4.5.*

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

Lowest available price from all providers
Mon Sep 21 2026 • llm-stats.com
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Moonshot AI
Kimi K3
Input tokens$2.85
Output tokens$14.25
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Kimi K3 accepts 1,048,576 input tokens compared to Grok 4.5's 500,000 tokens. Only Kimi K3 specifies output context (1,048,576 tokens).

xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Moonshot AI
Kimi K3
Input1,048,576 tokens
Output1,048,576 tokens
Mon Sep 21 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Grok 4.5 and Kimi K3 support multimodal inputs.

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

Grok 4.5

Text
Images
Audio
Video

Kimi K3

Text
Images
Audio
Video

License

Usage and distribution terms

Grok 4.5 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.

Grok 4.5

Proprietary

Closed source

Kimi K3

Kimi K3 License

Open weights

Release Timeline

When each model was launched

Both models were released on 2026-07-16.

They likely represent similar generations of model development.

Grok 4.5

Jul 16, 2026

2 months ago

Kimi K3

Jul 16, 2026

2 months ago

Knowledge Cutoff

When training data ends

Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Kimi K3'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 K3's cutoff date.

Grok 4.5

Feb 2026

Kimi K3

Provider Availability

Grok 4.5 is available from xAI. Kimi K3 is available from DeepInfra, Fireworks, Moonshot AI, Novita, Together.

Grok 4.5

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

Kimi K3

deepinfra logo
Deepinfra
Input Price:Input: $2.85/1MOutput Price:Output: $14.25/1M
fireworks logo
Fireworks
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
moonshot logo
Unknown Organization
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
novita logo
Novita
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
together logo
Together
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Grok 4.5 and Kimi K3 side-by-side, then vote on the output you prefer.

Grok 4.5
✓ Preferred
Kimi K3
Open in Playground

FAQ

Common questions about Grok 4.5 vs Kimi K3.

Which is better, Grok 4.5 or Kimi K3?

Kimi K3 leads the LLM Stats Score 53.0 to 45.4. Grok 4.5 is made by xAI and Kimi K3 is made by Moonshot AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Grok 4.5 compare to Kimi K3 in benchmarks?

Grok 4.5 scores GPQA: 93.0%, Terminal-Bench 2.1: 83.3%, SWE-Bench Pro: 64.7%, AA-Omniscience Index: 63.0%, DeepSWE 1.0: 62.0%. Kimi K3 scores MathVision: 97.8%, DeepSearchQA: 95.0%, GPQA: 93.5%, CharXiv-R: 91.3%, BrowseComp: 91.2%.

Is Grok 4.5 cheaper than Kimi K3?

Grok 4.5 is 1.4x cheaper for input tokens. Grok 4.5 costs $2.00/M input and $6.00/M output via xai. Kimi K3 costs $2.85/M input and $14.25/M output via deepinfra.

What are the context window sizes for Grok 4.5 and Kimi K3?

Grok 4.5 supports 500K tokens and Kimi K3 supports 1.0M 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 K3?

Key differences include LLM Stats Score (45.4 vs 53.0), context window (500K vs 1.0M), input pricing ($2.00 vs $2.85/M), licensing (Proprietary vs Kimi K3 License). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok 4.5 and Kimi K3?

Grok 4.5 is developed by xAI and Kimi K3 is developed by Moonshot AI.