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LLM Index

ChatGPT vs. Grok

A side-by-side comparison of release history, capabilities, licensing and model sizes.

Attribute ChatGPT Grok
Developer OpenAI xAI
Current generation GPT-5.6 Grok 4.5
Initial release 2022-11-30 2023-11-05
Instruct tuned Yes Yes
Coding Yes Yes
Finetuning Yes Yes
Open source No No
License NA NA
Model sizes Undisclosed Undisclosed
Links
Website Pricing
Website Pricing

ChatGPT

ChatGPT is OpenAI's consumer and business AI product, powered by the GPT model family. GPT-5.6 is the current generation for advanced reasoning, coding, computer use, and professional work.

ChatGPT launched in November 2022 on GPT-3.5 and later added GPT-4, GPT-4o, the o-series reasoning models, and GPT-5. OpenAI released GPT-5.6 in July 2026 across ChatGPT, Codex, and the API. The generation includes the flagship Sol tier, the balanced Terra tier, and the fast, cost-efficient Luna tier. GPT-5.5 Instant remains available for fast everyday conversations, while GPT-5.6 powers higher-effort reasoning options on eligible plans.

Further reading

Grok

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.

Further reading

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