Llama-3.1 Nemotron Ultra 253B vs Qwen3 Coder Next

Llama-3.1 Nemotron Ultra 253B

NVIDIA

Llama-3.1-Nemotron-Ultra-253B-v1 is a 253-billion-parameter model from NVIDIA, derived from Meta's Llama 3.1 405B using neural architecture search (NAS) compression combined with NVIDIA's Nemotron post-training pipeline, which recovers and exceeds the base model's capability after structural compression. Released in April 2025, it supports toggling between a standard instruction mode and an extended reasoning mode via system prompt, allowing the same model to handle both rapid responses and deliberate chain-of-thought tasks. It is the flagship of the Nemotron family, available open-weight on HuggingFace and through NVIDIA NIM for enterprise inference.

Alibaba / Qwen

Qwen3 Coder Next is a coding-specialized open-weight model from Alibaba's Qwen3 family, built on the Qwen3-Next architecture with hybrid attention and Mixture-of-Experts design optimized for local development and agentic coding workflows. It targets on-device and self-hosted deployments requiring a capable coding agent that can operate within consumer hardware constraints.