GPT-5.1 Codex vs Llama 3.1 Nemotron Nano 8B

GPT-5.1 Codex

OpenAI

GPT-5.1 Codex, released by OpenAI in November 2025, is a coding-specialized model from the GPT-5.1 family engineered for software engineering tasks including code generation, multi-file editing, and agentic development. It targets developers and automated coding pipelines requiring a GPT-5.1-generation model tuned for programming.

Llama 3.1 Nemotron Nano 8B

NVIDIA

Llama-3.1-Nemotron-Nano-8B-v1 is an 8-billion-parameter model from NVIDIA, developed as a fine-tuned variant of Meta's Llama 3.1 8B using NVIDIA's Nemotron post-training methodology, which applies reinforcement learning and process reward modeling to enhance instruction-following and reasoning capability over the base model. The Nano designation marks it as the entry-level member of the Nemotron family, optimized for efficient inference on a single GPU while delivering meaningfully improved performance on instruction alignment and agentic tasks compared to standard Llama 3.1. Released open-weight on HuggingFace, it is designed for deployment in NVIDIA-accelerated environments and supports NVIDIA NIM for enterprise inference.