Explainers

Short, sourced write-ups of pricing and model changes. Last checked Oct 19, 2026.

• OpenAI legacy model shutdown on Oct 23, 2026: what is retired and what replaces it

  gpt-4, gpt-3.5-turbo, gpt-4-turbo, o1, o3-mini, o4-mini, gpt-image-1 and their fine-tunes are shut down on Oct 23. Every affected model ID and its replacement.

• GPT-5.6 Sol promo pricing: $4 / $20 per 1M tokens, guaranteed at least through Nov 21, 2026

  The promo price, how long OpenAI guarantees it (at least through Nov 21, 2026), and what is not announced yet.