Model Comparison
GPT OSS 120B vs Kimi K3Which is better in 2026?
Kimi K3 significantly outperforms across most benchmarks. GPT OSS 120B is 33.3x cheaper per token.
Verdict: GPT OSS 120B vs Kimi K3 — which is better?
GPT OSS 120B (by OpenAI) and Kimi K3 (by Moonshot AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
GPT OSS 120B outperforms in 0 benchmarks, while Kimi K3 is better at 2 benchmarks (GPQA, Humanity's Last Exam). Kimi K3 significantly outperforms across most benchmarks.
On price, GPT OSS 120B is roughly 33.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT OSS 120B if…
- cost matters — it's about 33.3x cheaper per token
- you need open weights you can self-host or fine-tune
Choose Kimi K3 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
GPT OSS 120B outperforms in 0 benchmarks, while Kimi K3 is better at 2 benchmarks (GPQA, Humanity's Last Exam).
Kimi K3 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT OSS 120B ($0.09/1M tokens) is 33.3x cheaper than Kimi K3 ($3.00/1M tokens).
For output processing, GPT OSS 120B ($0.45/1M tokens) is 33.3x cheaper than Kimi K3 ($15.00/1M tokens).
In conclusion, Kimi K3 is more expensive than GPT OSS 120B.*
* Using a 3:1 ratio of input to output tokens
Model Size
Parameter count comparison
Kimi K3 has 2683.2B more parameters than GPT OSS 120B, making it 2297.3% larger.
Context Window
Maximum input and output token capacity
Kimi K3 accepts 1,048,576 input tokens compared to GPT OSS 120B's 131,072 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while GPT OSS 120B is limited to 131,072 tokens.
Input Capabilities
Supported data types and modalities
Kimi K3 supports multimodal inputs, whereas GPT OSS 120B does not.
Kimi K3 can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT OSS 120B
Kimi K3
Release Timeline
When each model was launched
GPT OSS 120B was released on 2025-08-05, while Kimi K3 was released on 2026-07-16.
Kimi K3 is 12 months newer than GPT OSS 120B.
Aug 5, 2025
11 months ago
Jul 16, 2026
1 weeks ago
11mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq. Kimi K3 is available from Moonshot AI.
GPT OSS 120B
Kimi K3
Outputs Comparison
Key Takeaways
GPT OSS 120B
View detailsOpenAI
Kimi K3
View detailsMoonshot AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT OSS 120B and Kimi K3 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT OSS 120B vs Kimi K3.