GPT-OSS-120B vs Mistral Small 3 24B

GPT-OSS-120B

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.

Mistral Small 3 24B

Mistral AI

Mistral Small 3 is a 24-billion-parameter open-weight language model from Mistral AI, released in January 2025 as an update to the Mistral Small line with targeted improvements to instruction-following, multilingual reasoning, and structured output quality. Released under Apache 2.0, it was designed for deployment on a single high-VRAM GPU, continuing Mistral's focus on practical efficiency over maximum scale. The model became a widely-used option for teams building internal tooling, customer-facing applications, and local inference pipelines that needed strong general capability without the operational overhead of larger models.