Model Comparison
GPT-5 nano vs GPT OSS 120BWhich is better in 2026?
GPT OSS 120B significantly outperforms across most benchmarks. GPT-5 nano is 1.3x cheaper per token.
Verdict: GPT-5 nano vs GPT OSS 120B — which is better?
GPT-5 nano (by OpenAI) and GPT OSS 120B (by OpenAI) 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-5 nano outperforms in 0 benchmarks, while GPT OSS 120B is better at 2 benchmarks (GPQA, Humanity's Last Exam). GPT OSS 120B significantly outperforms across most benchmarks.
On price, GPT-5 nano is roughly 1.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5 nano also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5 nano if…
- cost matters — it's about 1.3x cheaper per token
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped Aug 2025
Choose GPT OSS 120B if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5 nano outperforms in 0 benchmarks, while GPT OSS 120B is better at 2 benchmarks (GPQA, Humanity's Last Exam).
GPT OSS 120B significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5 nano ($0.05/1M tokens) is 1.8x cheaper than GPT OSS 120B ($0.09/1M tokens).
For output processing, GPT-5 nano ($0.40/1M tokens) is 1.1x cheaper than GPT OSS 120B ($0.45/1M tokens).
In conclusion, GPT OSS 120B is more expensive than GPT-5 nano.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5 nano accepts 400,000 input tokens compared to GPT OSS 120B's 131,072 tokens. GPT OSS 120B can generate longer responses up to 131,072 tokens, while GPT-5 nano is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
GPT-5 nano supports multimodal inputs, whereas GPT OSS 120B does not.
GPT-5 nano can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5 nano
GPT OSS 120B
License
Usage and distribution terms
GPT-5 nano is licensed under a proprietary license, while GPT OSS 120B uses Apache 2.0.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Apache 2.0
Open weights
Release Timeline
When each model was launched
GPT-5 nano was released on 2025-08-07, while GPT OSS 120B was released on 2025-08-05.
GPT-5 nano is 0 month newer than GPT OSS 120B.
Aug 7, 2025
10 months ago
2d newerAug 5, 2025
10 months ago
Knowledge Cutoff
When training data ends
GPT-5 nano has a documented knowledge cutoff of 2024-05-30, while GPT OSS 120B's cutoff date is not specified.
We can confirm GPT-5 nano's training data extends to 2024-05-30, but cannot make a direct comparison without GPT OSS 120B's cutoff date.
May 2024
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Provider Availability
GPT-5 nano is available from OpenAI. GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq.
GPT-5 nano
GPT OSS 120B
Outputs Comparison
Key Takeaways
GPT-5 nano
View detailsOpenAI
GPT OSS 120B
View detailsOpenAI
Detailed Comparison
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FAQ
Common questions about GPT-5 nano vs GPT OSS 120B.