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Claude Opus 4.5 vs Kimi K2.8 Preview

Comparing Claude Opus 4.5 and Kimi K2.8 Preview across benchmarks, pricing, and capabilities.

Anthropic · Moonshot AI · Updated for 2026

Which is better?

Claude Opus 4.5 and Kimi K2.8 Preview trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

Kimi K2.8 Preview 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 Claude Opus 4.5

  • you want predictable pricing at $5.00/M input and $25.00/M output

Choose Kimi K2.8 Preview

  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Claude Opus 4.5
Anthropic
Kimi K2.8 Preview
Moonshot AI
Benchmark wins
—
—
Input price
$5.00 / M
— / M
Output price
$25.00 / M
— / M
Context window
200,000
1,048,576

Individual benchmarks

11 reported for Claude Opus 4.5 · 0 for Kimi K2.8 Preview

No common benchmarks found

Claude Opus 4.5 and Kimi K2.8 Previewdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Kimi K2.8 Preview accepts 1,048,576 input tokens compared to Claude Opus 4.5's 200,000 tokens. Only Claude Opus 4.5 specifies output context (64,000 tokens).

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
Moonshot AI
Kimi K2.8 Preview
Input1,048,576 tokens
Output- tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 4.5 and Kimi K2.8 Preview support multimodal inputs.

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

Claude Opus 4.5

Text
Images
Audio
Video

Kimi K2.8 Preview

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.

Claude Opus 4.5

Proprietary

Closed source

Kimi K2.8 Preview

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Kimi K2.8 Preview was released on 2026-09-11.

Kimi K2.8 Preview is 10 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

9 months ago

Kimi K2.8 Preview

Sep 11, 2026

3 days ago

9mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Kimi K2.8 Preview's cutoff date is not specified.

We can confirm Claude Opus 4.5's training data extends to 2025-03-31, but cannot make a direct comparison without Kimi K2.8 Preview's cutoff date.

Claude Opus 4.5

Mar 2025

Kimi K2.8 Preview

—

Provider Availability

Claude Opus 4.5 is available from Anthropic. Kimi K2.8 Preview is available from Moonshot AI.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

Kimi K2.8 Preview

moonshot logo
Unknown Organization
* 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 Claude Opus 4.5 and Kimi K2.8 Preview side-by-side, then vote on the output you prefer.

Claude Opus 4.5
✓ Preferred
Kimi K2.8 Preview
Open in Playground

FAQ

Common questions about Claude Opus 4.5 vs Kimi K2.8 Preview.

Which is better, Claude Opus 4.5 or Kimi K2.8 Preview?

Claude Opus 4.5 (Anthropic) and Kimi K2.8 Preview (Moonshot AI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Claude Opus 4.5 compare to Kimi K2.8 Preview in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%.

What are the context window sizes for Claude Opus 4.5 and Kimi K2.8 Preview?

Claude Opus 4.5 supports 200K tokens and Kimi K2.8 Preview 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 Claude Opus 4.5 and Kimi K2.8 Preview?

Key differences include context window (200K vs 1.0M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and Kimi K2.8 Preview?

Claude Opus 4.5 is developed by Anthropic and Kimi K2.8 Preview is developed by Moonshot AI.

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