The AI arena is free today

Open Superagent

Claude Opus 5 vs Kimi K2-Instruct-0905

Claude Opus 5 leads the LLM Stats Score 54.9 to 21.6.

Anthropic · Moonshot AI · Updated for 2026

Which is better?

Claude Opus 5 leads the overall LLM Stats Score 54.9 to 21.6, ranking #5 overall.

In the 1 individual benchmarks reported for both models, Claude Opus 5 wins 1; this is a narrower head-to-head signal than the composite indexes.

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

Choose Claude Opus 5

  • overall performance matters — it scores 54.9 and ranks #5 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Jul 2026

Choose Kimi K2-Instruct-0905

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Opus 5
Anthropic
Kimi K2-Instruct-0905
Moonshot AI
Core performance indexes
LLM Stats Score
54.9
#5
21.6
#185
Reasoning
53.9
#4
21.8
#175
Coding
41.9
#9
9.8
#168
Agents
40.0
#7
-4.1
#179
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$5.00 / M
— / M
Output price
$25.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5
Kimi K2-Instruct-0905
Tool use
27.9#21
6.6#144
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

13 reported for Claude Opus 5 · 29 for Kimi K2-Instruct-0905

1 shared

Claude Opus 5 outperforms in 1 benchmarks (Humanity's Last Exam), while Kimi K2-Instruct-0905 is better at 0 benchmarks.

Claude Opus 5 significantly outperforms across most benchmarks.

Mon Sep 14 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Opus 5 specifies input context (1,000,000 tokens). Only Claude Opus 5 specifies output context (128,000 tokens).

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2-Instruct-0905
Input- tokens
Output- tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Opus 5 supports multimodal inputs, whereas Kimi K2-Instruct-0905 does not.

Claude Opus 5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5

Text
Images
Audio
Video

Kimi K2-Instruct-0905

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5 is licensed under a proprietary license, while Kimi K2-Instruct-0905 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Opus 5

Proprietary

Closed source

Kimi K2-Instruct-0905

MIT

Open weights

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while Kimi K2-Instruct-0905 was released on 2025-09-05.

Claude Opus 5 is 11 months newer than Kimi K2-Instruct-0905.

Claude Opus 5

Jul 24, 2026

1 months ago

10mo newer
Kimi K2-Instruct-0905

Sep 5, 2025

1.0 years 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

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Opus 5 and Kimi K2-Instruct-0905 side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
Kimi K2-Instruct-0905
Open in Playground

FAQ

Common questions about Claude Opus 5 vs Kimi K2-Instruct-0905.

Which is better, Claude Opus 5 or Kimi K2-Instruct-0905?

Claude Opus 5 leads the LLM Stats Score 54.9 to 21.6. Claude Opus 5 is made by Anthropic and Kimi K2-Instruct-0905 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 Claude Opus 5 compare to Kimi K2-Instruct-0905 in benchmarks?

Claude Opus 5 scores BrowseComp: 90.8%, BioMysteryBench: 90.1%, OSWorld 2.0: 70.6%, DeepSWE 1.1: 68.8%, Humanity's Last Exam: 64.7%. Kimi K2-Instruct-0905 scores MATH-500: 97.4%, MMLU-Redux: 92.7%, IFEval: 89.8%, AutoLogi: 89.5%, MMLU: 89.5%.

What are the context window sizes for Claude Opus 5 and Kimi K2-Instruct-0905?

Claude Opus 5 supports 1.0M tokens and Kimi K2-Instruct-0905 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 5 and Kimi K2-Instruct-0905?

Key differences include LLM Stats Score (54.9 vs 21.6), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5 and Kimi K2-Instruct-0905?

Claude Opus 5 is developed by Anthropic and Kimi K2-Instruct-0905 is developed by Moonshot AI.

Related comparisons