Model Comparison

Kimi K3 vs Grok 4.5Which is better in 2026?

Kimi K3 significantly outperforms across most benchmarks. Grok 4.5 is 2.0x cheaper per token.

Verdict: Kimi K3 vs Grok 4.5 — which is better?

Kimi K3 (by Moonshot AI) and Grok 4.5 (by xAI) 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.

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

On price, Grok 4.5 is roughly 2.0x 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.

Choose Kimi K3 if…

  • you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose Grok 4.5 if…

  • cost matters — it's about 2.0x cheaper per token

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

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

Kimi K3 significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok 4.5 costs less

For input processing, Kimi K3 ($3.00/1M tokens) is 1.5x more expensive than Grok 4.5 ($2.00/1M tokens).

For output processing, Kimi K3 ($15.00/1M tokens) is 2.5x more expensive than Grok 4.5 ($6.00/1M 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
Fri Jul 17 2026 • llm-stats.com
Moonshot AI
Kimi K3
Input tokens$3.00
Output tokens$15.00
Best providerUnknown Organization
xAI
Grok 4.5
Input tokens$2.00
Output tokens$6.00
Best providerxAI
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).

Moonshot AI
Kimi K3
Input1,048,576 tokens
Output1,048,576 tokens
xAI
Grok 4.5
Input500,000 tokens
Output- tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Kimi K3 and Grok 4.5 support multimodal inputs.

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

Kimi K3

Text
Images
Audio
Video

Grok 4.5

Text
Images
Audio
Video

Release Timeline

When each model was launched

Kimi K3 was released on 2026-07-16, while Grok 4.5 was released on 2026-07-08.

Kimi K3 is 0 month newer than Grok 4.5.

Kimi K3

Jul 16, 2026

1 days ago

1w newer
Grok 4.5

Jul 8, 2026

1 weeks ago

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 K3 is available from Moonshot AI. Grok 4.5 is available from xAI.

Kimi K3

moonshot logo
Unknown Organization
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

Grok 4.5

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Moonshot AI
Larger context window (1,048,576 tokens)
Has open weights
Higher DeepSWE score (67.5% vs 53.0%)
Higher GDPval-AA score (55.6% vs 51.4%)
Higher GPQA score (93.5% vs 93.0%)
Higher SWE-Marathon score (42.0% vs 29.0%)
Higher Terminal-Bench 2.1 score (88.3% vs 83.3%)
xAI
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

Interactive Arena

Judge for yourself.

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

Kimi K3
✓ Preferred
Grok 4.5
Open in Playground
AI Model Comparison Table
Feature
Moonshot AI
Kimi K3
xAI
Grok 4.5

FAQ

Common questions about Kimi K3 vs Grok 4.5.

Which is better, Kimi K3 or Grok 4.5?

Kimi K3 significantly outperforms across most benchmarks. Kimi K3 is made by Moonshot AI and Grok 4.5 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Kimi K3 compare to Grok 4.5 in benchmarks?

Kimi K3 scores MathVision: 97.8%, DeepSearchQA: 95.0%, GPQA: 93.5%, CharXiv-R: 91.3%, BrowseComp: 91.2%. 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%.

Is Kimi K3 cheaper than Grok 4.5?

Grok 4.5 is 1.5x cheaper for input tokens. Kimi K3 costs $3.00/M input and $15.00/M output via moonshot. Grok 4.5 costs $2.00/M input and $6.00/M output via xai.

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

Kimi K3 supports 1.0M tokens and Grok 4.5 supports 500K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Kimi K3 and Grok 4.5?

Key differences include context window (1.0M vs 500K), input pricing ($3.00 vs $2.00/M), licensing (Unknown vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Kimi K3 and Grok 4.5?

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

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