Comprehensive side-by-side LLM comparison
GPT-OSS-120B leads with 9.2% higher average benchmark score. o3 offers 167.9K more tokens in context window than GPT-OSS-120B. o3 is $Infinity cheaper per million tokens. o3 supports multimodal inputs. Overall, GPT-OSS-120B is the stronger choice for coding tasks.
OpenAI
GPT-OSS-120B, released by OpenAI in August 2025, is an open-weight large language model with 120 billion parameters distributed under the Apache 2.0 license. It represents OpenAI's entry into the open-source model space, enabling developers to self-host and fine-tune a GPT-5-generation-class model. GPT-OSS-120B targets research applications, on-premises deployments, and custom fine-tuning workflows requiring a large open-weight base model.
OpenAI
OpenAI o3, released by OpenAI in April 2025, is a large reasoning model that applies extended chain-of-thought processing to deliver improved performance on complex math, science, and coding tasks. It features a 200K token context window and native image understanding, with demonstrated strong results on mathematics and software engineering benchmarks. o3 targets demanding analytical and engineering tasks where deliberate, multi-step reasoning produces significantly better outcomes than direct generation.
3 months newer

o3
OpenAI
2025-04-16

GPT-OSS-120B
OpenAI
2025-08
Cost per million tokens (USD)
GPT-OSS-120B
o3
Context window and performance specifications
Average performance across 1 common benchmarks
GPT-OSS-120B
o3
Performance comparison across key benchmark categories
GPT-OSS-120B
o3
Available providers and their performance metrics
GPT-OSS-120B
Hugging Face
o3
GPT-OSS-120B
o3
GPT-OSS-120B
o3
OpenAI