Models

Grok 4.5 vs Kimi K3

Compare Grok 4.5 from Grok and Kimi K3 from Moonshot AI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.

GrokGrok 4.5Moonshot AIKimi K3
Grok logo
Grok 4.5
Grok · text, image → text

Grok 4.5 was trained on datasets spanning knowledge in coding, science, engineering, and math. With both intelligent and efficient reasoning, Grok 4.5 excels at real engineering tasks and exceeds comparable leading models at these tasks.

Input$2 /M
Output$6 /M
Cache read$0.5 /M
10% off
Moonshot AI logo
Kimi K3
Moonshot AI · text, image, video → text

Kimi K3 is Kimi’s flagship model for long-horizon coding and end-to-end knowledge work, with a 1M-token context window and industry-leading intelligence.

Input$3$2.7 /M
Output$15$13.5 /M
Cache read$0.3$0.27 /M

Pricing & Specifications

Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.

Grok 4.5
Kimi K3
Input /M
$2
$3$2.710%
Output /M
$6
$15$13.510%
Cache read /M
$0.5
$0.3$0.2710%
Context length
500,000
1,048,576
Max output
500,000
1,048,576
Time to First Token
3.5 s
0.9 s
Throughput
26.6 tok/s
73.1 tok/s
Modalities
textimage
textimagevideo
Supported Parameters
thinkingtoolsfunction callingstructured outputslong context
thinkingfunction callingstructured outputs
API Formats
Released
July 2026
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Promotional prices show the discounted rate; see each model page for promotion windows.

Activity Past 30 Days

Daily traffic served through AIHubMix — how demand for each model is trending.

grok-4.5kimi-k3

Tokens / day

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Requests / day

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Performance Past 3 Days

Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.

grok-4.5kimi-k3

Throughput (tok/s)

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TTFT (s)

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Uptime (%)

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LMArena Benchmarks

LMArena ratings by capability (Bradley-Terry, commonly called Elo). Higher is better.

Text
grok-4.5kimi-k3
1420146015001540
Overall
14711486
Coding
15231531
Math
14791479
Hard prompts
14951505
Instruction following
14661479
Multi-turn
14761499
Creative writing
14511470
Longer query
14871502
Chinese
15121527
English
14761491

Source: LMArena (arena.ai) leaderboard, imported by AIHubMix. Models without published ratings are omitted per chart.

Cost calculator

Estimate your monthly bill for the same workload on each model.

Grok 4.5
$210 /mo
Kimi K3
$405$365 /mo

Monthly = daily × 30. Discounted rates applied where a promotion is active.

FAQ

Which is cheaper: Grok 4.5, Kimi K3?

Grok 4.5: $6/M output tokens; Kimi K3: $13.5/M. Use the cost calculator above to estimate your own workload.

How do their coding arena scores compare?

Kimi K3: 1531; Grok 4.5: 1523 (LMArena coding leaderboard).

Which responds faster?

Kimi K3: 0.9s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.

How large is each context window?

Grok 4.5 accepts 500,000 and Kimi K3 accepts 1,048,576 input tokens. Maximum output per request is 500,000 tokens on Grok 4.5 and 1,048,576 tokens on Kimi K3.

Which one generates tokens faster?

Kimi K3 at 73.1 tok/s and Grok 4.5 at 26.6 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

Grok 4.5 accepts text and image input and supports thinking, tool calling, function calling, structured outputs and long context; Kimi K3 accepts text, image and video input and supports thinking, function calling and structured outputs.

Can I call Grok 4.5 and Kimi K3 with the same API key?

Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.

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