OpenAI LLM Medium Closed weights

GPT-5.6 Sol

126 days since OpenAI announced it · 9 Jul 2026

GPT-5.6 Sol is a closed-weights LLM from OpenAI, announced 9 Jul 2026. Its context window is 1.05M tokens.

Input: —; per 1M tokens
Cache write: —; per 1M tokens
Cache read: —; per 1M tokens
Output: —; per 1M tokens
Context window: 1.05M; tokens
Parameters: —; not disclosed

No price on the lab’s own pages.

Announcement: openai.com/index/gpt-5-6
Docs: developers.openai.com/api/docs/models/gpt-5.6-sol

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OpenAI · Medium

closed weights

A new one every ~75 days — due in ~58d.

GPT-6.1 Terra +27d 26 Oct 2026
GPT-6.1 Sol +7d 29 Sep 2026
GPT-6 Sol +75d 22 Sep 2026
GPT-5.6 Terra +0d 9 Jul 2026
GPT-5.6 Sol +114d 9 Jul 2026
GPT-5.4 mini +222d 17 Mar 2026
GPT-5 mini 7 Aug 2025

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GPT-6 Rosalind 30 Oct 2026
GPT-6 Luna 22 Sep 2026
GPT Image 2.5 Flare 8 Sep 2026
GPT Image 2.5 Sunburst 8 Sep 2026
GPT-6 Astra 3 Sep 2026

Facts last updated 1 Nov 2026, from OpenAI’s own pages.