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GPT OSS 120B vs Kimi K2.8 Preview

Comparing GPT OSS 120B and Kimi K2.8 Preview across benchmarks, pricing, and capabilities.

OpenAI · Moonshot AI · Updated for 2026

Which is better?

GPT OSS 120B 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 GPT OSS 120B

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

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.

GPT OSS 120B
OpenAI
Kimi K2.8 Preview
Moonshot AI
Benchmark wins
—
—
Input price
$0.04 / M
— / M
Output price
$0.17 / M
— / M
Context window
131,072
1,048,576

Individual benchmarks

7 reported for GPT OSS 120B · 0 for Kimi K2.8 Preview

No common benchmarks found

GPT OSS 120B 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 GPT OSS 120B's 131,072 tokens. Only GPT OSS 120B specifies output context (131,072 tokens).

OpenAI
GPT OSS 120B
Input131,072 tokens
Output131,072 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

Kimi K2.8 Preview supports multimodal inputs, whereas GPT OSS 120B does not.

Kimi K2.8 Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT OSS 120B

Text
Images
Audio
Video

Kimi K2.8 Preview

Text
Images
Audio
Video

License

Usage and distribution terms

GPT OSS 120B is licensed under Apache 2.0, while Kimi K2.8 Preview uses a proprietary license.

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

GPT OSS 120B

Apache 2.0

Open weights

Kimi K2.8 Preview

Proprietary

Closed source

Release Timeline

When each model was launched

GPT OSS 120B was released on 2025-08-05, while Kimi K2.8 Preview was released on 2026-09-11.

Kimi K2.8 Preview is 13 months newer than GPT OSS 120B.

GPT OSS 120B

Aug 5, 2025

1.1 years ago

Kimi K2.8 Preview

Sep 11, 2026

3 days ago

1.1yr newer

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

GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq. Kimi K2.8 Preview is available from Moonshot AI.

GPT OSS 120B

deepinfra logo
Deepinfra
Input Price:Input: $0.04/1MOutput Price:Output: $0.17/1M
novita logo
Novita
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
fireworks logo
Fireworks
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
groq logo
Groq
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M

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 GPT OSS 120B and Kimi K2.8 Preview side-by-side, then vote on the output you prefer.

GPT OSS 120B
✓ Preferred
Kimi K2.8 Preview
Open in Playground

FAQ

Common questions about GPT OSS 120B vs Kimi K2.8 Preview.

Which is better, GPT OSS 120B or Kimi K2.8 Preview?

GPT OSS 120B (OpenAI) 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 GPT OSS 120B compare to Kimi K2.8 Preview in benchmarks?

GPT OSS 120B scores MMLU: 90.0%, CodeForces: 82.1%, GPQA: 80.1%, TAU-bench Retail: 67.8%, HealthBench: 57.6%.

What are the context window sizes for GPT OSS 120B and Kimi K2.8 Preview?

GPT OSS 120B supports 131K 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 GPT OSS 120B and Kimi K2.8 Preview?

Key differences include context window (131K vs 1.0M), multimodal support (no vs yes), licensing (Apache 2.0 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT OSS 120B and Kimi K2.8 Preview?

GPT OSS 120B is developed by OpenAI and Kimi K2.8 Preview is developed by Moonshot AI.

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