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Kimi K2.8 Preview vs Seed 2.1 Pro

Comparing Kimi K2.8 Preview and Seed 2.1 Pro across benchmarks, pricing, and capabilities.

Moonshot AI · ByteDance · Updated for 2026

Which is better?

Kimi K2.8 Preview and Seed 2.1 Pro trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

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

Choose Kimi K2.8 Preview

  • you want the most recent training data — it shipped Sep 2026

Choose Seed 2.1 Pro

  • you are already invested in the ByteDance ecosystem

At a glance

The differences that matter most.

Kimi K2.8 Preview
Moonshot AI
Seed 2.1 Pro
ByteDance
Benchmark wins
—
—
Input price
— / M
— / M
Output price
— / M
— / M
Context window
1,048,576
—

Individual benchmarks

0 reported for Kimi K2.8 Preview · 94 for Seed 2.1 Pro

No common benchmarks found

Kimi K2.8 Preview and Seed 2.1 Prodon'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

Only Kimi K2.8 Preview specifies input context (1,048,576 tokens).

Moonshot AI
Kimi K2.8 Preview
Input1,048,576 tokens
Output- tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Kimi K2.8 Preview and Seed 2.1 Pro support multimodal inputs.

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

Kimi K2.8 Preview

Text
Images
Audio
Video

Seed 2.1 Pro

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.

Kimi K2.8 Preview

Proprietary

Closed source

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Kimi K2.8 Preview was released on 2026-09-11, while Seed 2.1 Pro was released on 2026-06-24.

Kimi K2.8 Preview is 3 months newer than Seed 2.1 Pro.

Kimi K2.8 Preview

Sep 11, 2026

1 weeks ago

2mo newer
Seed 2.1 Pro

Jun 24, 2026

2 months 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 Kimi K2.8 Preview and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

Kimi K2.8 Preview
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about Kimi K2.8 Preview vs Seed 2.1 Pro.

Which is better, Kimi K2.8 Preview or Seed 2.1 Pro?

Kimi K2.8 Preview (Moonshot AI) and Seed 2.1 Pro (ByteDance) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Kimi K2.8 Preview compare to Seed 2.1 Pro in benchmarks?

Seed 2.1 Pro scores CharXiv-D: 95.5%, MathVision: 94.5%, MathVista: 90.7%, MathVerse: 89.7%, Video-MME: 89.2%.

What are the context window sizes for Kimi K2.8 Preview and Seed 2.1 Pro?

Kimi K2.8 Preview supports 1.0M tokens and Seed 2.1 Pro supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes Kimi K2.8 Preview and Seed 2.1 Pro?

Kimi K2.8 Preview is developed by Moonshot AI and Seed 2.1 Pro is developed by ByteDance.

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