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Claude vs. Grok

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

Attribute Claude Grok
Developer Anthropic xAI
Current generation Claude Opus 5 Grok 4.5
Initial release 2023-03-14 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

Claude

Claude is Anthropic's family of safety-focused language models for coding, agents, reasoning, and knowledge work. Claude Opus 5 is the current Opus generation.

Claude is Anthropic's flagship model family and was originally trained using the company's Constitutional AI feedback method. Anthropic introduced the Claude 3 Haiku, Sonnet, and Opus tiers in 2024, added extended thinking with Claude 3.7 in 2025, and launched the Claude 4 generation for coding and agent workflows in May 2025. Claude Opus 5, released in July 2026, adds a one-million-token context window, thinking by default, deeper test-time reasoning, and stronger long-horizon coding, multi-agent, vision, and enterprise-work capabilities.

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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