Comprehensive side-by-side LLM comparison
Both models show comparable benchmark performance. Grok 3 mini offers 15.4K more tokens in context window than GPT-OSS-120B. Grok 3 mini is $Infinity cheaper per million tokens. Both models have their strengths depending on your specific coding needs.
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.
xAI
Grok 3 mini, released by xAI alongside Grok 3 in February 2025, is a compact reasoning model from the Grok 3 family featuring RL-enhanced Think mode for extended chain-of-thought processing. It features a 131K token context window and targets STEM tasks, mathematics, and coding applications where cost-efficient reasoning with configurable depth is required.
5 months newer

Grok 3 mini
xAI
2025-02-17

GPT-OSS-120B
OpenAI
2025-08
Cost per million tokens (USD)
GPT-OSS-120B
Grok 3 mini
Context window and performance specifications
Average performance across 1 common benchmarks
GPT-OSS-120B
Grok 3 mini
Performance comparison across key benchmark categories
GPT-OSS-120B
Grok 3 mini
Available providers and their performance metrics
GPT-OSS-120B
Hugging Face
Grok 3 mini
GPT-OSS-120B
Grok 3 mini
GPT-OSS-120B
Grok 3 mini
xAI