Grok

Reasoning model from xAI (Elon Musk's AI company), released on 17 February 2025. Trained on the Colossus supercluster, with 'Think' reasoning and DeepSearch plus real-time access to X. Proprietary access via the Grok app and API.

Grok 4 is xAI's reasoning model from July 2025 — text and image input, 256k context, trained via reinforcement learning on the 200,000-GPU Colossus cluster.

Grok 4.1 is xAIs AI model released in November 2025. It delivers more natural dialogue, fewer hallucinations and better style control, and comes in two variants: one that answers directly and one that reasons before responding (Thinking).

Grok 4.3 is xAIs reasoning-oriented model from April 2026 — with a 1M-token context, native video input and a focus on agentic workflows and factual accuracy.

Grok 4.5 is xAI's July 2026 frontier model for coding, agentic tasks and knowledge work — high token efficiency at $2 input and $6 output per 1M tokens.

Grok 4.6 (August 2026) is xAIs flagship model for long-running agentic work — 500k-token context, text and image input, tiered pricing from 2/6 USD per million tokens.