GPT OSS 120B vs o3
Both models are evenly matched across the benchmarks. GPT OSS 120B is 19.4x cheaper per token.
OpenAI · OpenAI · Updated for 2026
Which is better?
GPT OSS 120B outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 1 benchmark (GPQA). Both models are evenly matched across the benchmarks.
On price, GPT OSS 120B is roughly 19.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
o3 also accepts a larger context window (200,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose GPT OSS 120B
- cost matters — it's about 19.4x cheaper per token
- you want the most recent training data — it shipped Aug 2025
- you need open weights you can self-host or fine-tune
Choose o3
- you process long inputs — it offers a 200,000 token context window
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
GPT OSS 120B outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 1 benchmark (GPQA).
Both models are evenly matched across the benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT OSS 120B ($0.09/1M tokens) is 22.2x cheaper than o3 ($2.00/1M tokens).
For output processing, GPT OSS 120B ($0.45/1M tokens) is 17.8x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than GPT OSS 120B.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
o3 accepts 200,000 input tokens compared to GPT OSS 120B's 131,072 tokens. GPT OSS 120B can generate longer responses up to 131,072 tokens, while o3 is limited to 100,000 tokens.
Input Capabilities
Supported data types and modalities
o3 supports multimodal inputs, whereas GPT OSS 120B does not.
o3 can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT OSS 120B
o3
License
Usage and distribution terms
GPT OSS 120B is licensed under Apache 2.0, while o3 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
Apache 2.0
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
GPT OSS 120B was released on 2025-08-05, while o3 was released on 2025-04-16.
GPT OSS 120B is 4 months newer than o3.
Aug 5, 2025
1.1 years ago
3mo newerApr 16, 2025
1.4 years ago
Knowledge Cutoff
When training data ends
o3 has a documented knowledge cutoff of 2024-05-31, while GPT OSS 120B's cutoff date is not specified.
We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without GPT OSS 120B's cutoff date.
—
May 2024
Provider Availability
GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq. o3 is available from OpenAI.
GPT OSS 120B
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT OSS 120B and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT OSS 120B vs o3.