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GPT OSS 120B vs Kimi K2-Thinking-0905

Kimi K2-Thinking-0905 leads the LLM Stats Score 36.0 to 28.8. GPT OSS 120B is 12.1x cheaper per token.

OpenAI · Moonshot AI · Updated for 2026

Which is better?

Kimi K2-Thinking-0905 leads the overall LLM Stats Score 36.0 to 28.8, ranking #80 overall.

In the 3 individual benchmarks reported for both models, Kimi K2-Thinking-0905 wins 3; this is a narrower head-to-head signal than the composite indexes.

On price, GPT OSS 120B is roughly 12.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Kimi K2-Thinking-0905 also accepts a larger context window (262,144 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

  • cost matters — it's about 12.1x cheaper per token

Choose Kimi K2-Thinking-0905

  • overall performance matters — it scores 36.0 and ranks #80 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 3 of 3 exact shared results
  • you process long inputs — it offers a 262,144 token context window
  • you want the most recent training data — it shipped Sep 2025

At a glance

The differences that matter most.

Core performance indexes
28.8
#131
36.0
#80
23.0
#165
36.3
#73
Cost, coverage & limits
Benchmark wins
0 of 3
3 of 3
Input price
$0.04 / M
$0.47 / M
Output price
$0.17 / M
$2.00 / M
Context window
131,072
262,144

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT OSS 120B
Kimi K2-Thinking-0905
23.3#131
38.0#27
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for GPT OSS 120B · 21 for Kimi K2-Thinking-0905

3 shared

GPT OSS 120B outperforms in 0 benchmarks, while Kimi K2-Thinking-0905 is better at 3 benchmarks (GPQA, HealthBench, Humanity's Last Exam).

Kimi K2-Thinking-0905 significantly outperforms across most benchmarks.

Mon Sep 14 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT OSS 120B costs less

For input processing, GPT OSS 120B ($0.04/1M tokens) is 12.7x cheaper than Kimi K2-Thinking-0905 ($0.47/1M tokens).

For output processing, GPT OSS 120B ($0.17/1M tokens) is 11.8x cheaper than Kimi K2-Thinking-0905 ($2.00/1M tokens).

In conclusion, Kimi K2-Thinking-0905 is more expensive than GPT OSS 120B.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Sep 14 2026 • llm-stats.com
OpenAI
GPT OSS 120B
Input tokens$0.04
Output tokens$0.17
Best providerDeepinfra
Moonshot AI
Kimi K2-Thinking-0905
Input tokens$0.47
Output tokens$2.00
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue

Model Size

Parameter count comparison

883.2B diff

Kimi K2-Thinking-0905 has 883.2B more parameters than GPT OSS 120B, making it 756.2% larger.

OpenAI
GPT OSS 120B
116.8Bparameters
Moonshot AI
Kimi K2-Thinking-0905
1.0Tparameters
116.8B
GPT OSS 120B
1000.0B
Kimi K2-Thinking-0905

Context Window

Maximum input and output token capacity

Kimi K2-Thinking-0905 accepts 262,144 input tokens compared to GPT OSS 120B's 131,072 tokens. Kimi K2-Thinking-0905 can generate longer responses up to 262,144 tokens, while GPT OSS 120B is limited to 131,072 tokens.

OpenAI
GPT OSS 120B
Input131,072 tokens
Output131,072 tokens
Moonshot AI
Kimi K2-Thinking-0905
Input262,144 tokens
Output262,144 tokens
Mon Sep 14 2026 • llm-stats.com

License

Usage and distribution terms

GPT OSS 120B is licensed under Apache 2.0, while Kimi K2-Thinking-0905 uses MIT.

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-Thinking-0905

MIT

Open weights

Release Timeline

When each model was launched

GPT OSS 120B was released on 2025-08-05, while Kimi K2-Thinking-0905 was released on 2025-09-05.

Kimi K2-Thinking-0905 is 1 month newer than GPT OSS 120B.

GPT OSS 120B

Aug 5, 2025

1.1 years ago

Kimi K2-Thinking-0905

Sep 5, 2025

1.0 years ago

1mo 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-Thinking-0905 is available from DeepInfra, Novita, Fireworks.

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-Thinking-0905

deepinfra logo
Deepinfra
Input Price:Input: $0.47/1MOutput Price:Output: $2.00/1M
novita logo
Novita
Input Price:Input: $0.48/1MOutput Price:Output: $2.00/1M
fireworks logo
Fireworks
Input Price:Input: $0.60/1MOutput Price:Output: $2.50/1M
* 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-Thinking-0905 side-by-side, then vote on the output you prefer.

GPT OSS 120B
✓ Preferred
Kimi K2-Thinking-0905
Open in Playground

FAQ

Common questions about GPT OSS 120B vs Kimi K2-Thinking-0905.

Which is better, GPT OSS 120B or Kimi K2-Thinking-0905?

Kimi K2-Thinking-0905 leads the LLM Stats Score 36.0 to 28.8. GPT OSS 120B is made by OpenAI and Kimi K2-Thinking-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 GPT OSS 120B compare to Kimi K2-Thinking-0905 in benchmarks?

GPT OSS 120B scores MMLU: 90.0%, CodeForces: 82.1%, GPQA: 80.1%, TAU-bench Retail: 67.8%, HealthBench: 57.6%. Kimi K2-Thinking-0905 scores AIME 2025: 100.0%, HMMT 2025: 97.5%, MMLU-Redux: 94.4%, FRAMES: 87.0%, MMLU-Pro: 84.6%.

Is GPT OSS 120B cheaper than Kimi K2-Thinking-0905?

GPT OSS 120B is 12.7x cheaper for input tokens. GPT OSS 120B costs $0.04/M input and $0.17/M output via deepinfra. Kimi K2-Thinking-0905 costs $0.47/M input and $2.00/M output via deepinfra.

What are the context window sizes for GPT OSS 120B and Kimi K2-Thinking-0905?

GPT OSS 120B supports 131K tokens and Kimi K2-Thinking-0905 supports 262K 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-Thinking-0905?

Key differences include LLM Stats Score (28.8 vs 36.0), context window (131K vs 262K), input pricing ($0.04 vs $0.47/M), licensing (Apache 2.0 vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT OSS 120B and Kimi K2-Thinking-0905?

GPT OSS 120B is developed by OpenAI and Kimi K2-Thinking-0905 is developed by Moonshot AI.