Introducing GPT-6 Sol and Luna

Summary

OpenAI's announcement of two GPT-6 models below the flagship GPT-6 Astra: Sol and Luna, trained with similar methods to Astra but faster and cheaper. The page itself could not be fetched (HTTP 403); details come from OpenAI's search snippet and developer forum post.

Key points

• GPT-6 Astra, the flagship, was introduced in early September 2026.
• Sol and Luna bring Astra's training advances to cheaper, faster models.
• API prices were cut 50% compared with GPT-5.6 promotional pricing.
• Available in ChatGPT and Codex for paid plans at launch.
• An update, GPT-6.1 Sol, was reported on 2026-09-29.

Why it matters

Completes the GPT-6 lineup across three price tiers, replacing the GPT-5.x series.