xAI LLM Big Closed weights

Grok 4.5

119 days since xAI announced it · 16 Jul 2026

Grok 4.5 is a closed-weights LLM from xAI, announced 16 Jul 2026. It costs $2 per 1M input tokens and $6 per 1M output tokens. Its context window is 500K tokens.

Input: $2; per 1M tokens
Cache write: —; per 1M tokens
Cache read: $0.30; per 1M tokens
Output: $6; per 1M tokens
Context window: 500K; tokens
Parameters: —; not disclosed

Announcement: x.ai/news/grok-4-5
Docs: docs.x.ai/developers/models/grok-4.5

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xAI · Big

closed weights

A new one every ~40 days — due now.

Grok 4.7 +40d 21 Sep 2026
Grok 4.6 +27d 12 Aug 2026
Grok 4.5 +241d 16 Jul 2026
Grok 4.1 +131d 17 Nov 2025
Grok 4 9 Jul 2025