GPT-J vs. Grok

Overview

GPT-J is a model released by EleutherAI shortly after its release of GPTNeo, with the aim of delveoping an open source model with capabilities similar to OpenAI's GPT-3 model. With a larger size than GPTNeo, GPT-J also performs better on various benchmarks.

Initial release: 2021-06-09

Reference

https://huggingface.co/EleutherAI/gpt-j-6b

Further Reading

Overview

Grok is the proprietary model family available through xAI's products and API. Grok 4.5 is the current generation, focused on coding, agentic tasks, reasoning, and knowledge work.

xAI introduced Grok in November 2023 and released the weights for Grok-1 under Apache 2.0 in March 2024. Later generations are proprietary and available through Grok, X, and the xAI API. Grok 4.5, released in July 2026, is xAI's current flagship model for software engineering, tool-driven agents, complex reasoning, and professional knowledge work.

Initial release: 2023-11-05

Current generation: Grok 4.5

Reference

https://x.ai/news/grok-4-5

Further Reading

• https://github.com/xai-org/grok-1/tree/main
• https://x.ai/news/grok-4-5