OpenAI Codex changelog

GPT-5.5 retired from Codex and ChatGPT

At noon PDT (19:00 UTC) on October 14, 2026, GPT-5.5 retired from Codex for ChatGPT sign-in. Replacements are GPT-6.1 Sol on paid plans and GPT-6 Luna on Free and Go. API-key sessions are not affected.

Who is affected:

Codex and ChatGPT users and scheduled tasks that selected GPT-5.5.

Action needed:

Replace gpt-5.5 with gpt-6.1-sol in defaults, custom agents, scheduled tasks and scripts.

GPT-5.3-Codex-Spark research preview retired

GPT-5.3-Codex-Spark was deprecated on September 14, 2026 and is no longer available in the ChatGPT desktop app, Codex CLI or IDE extension.

Who is affected:

Codex users and scripts that select gpt-5.3-codex-spark.

Action needed:

Switch to a recommended model. Use Fast mode for speed.

GPT-5.5 to retire from ChatGPT, ChatGPT Work and Codex on October 14

OpenAI announced GPT-5.5 would retire from ChatGPT, ChatGPT Work and Codex on all plans on October 14, 2026. The API is not affected.

Who is affected:

ChatGPT and Codex users and admins who select GPT-5.5.

Action needed:

Update workspace defaults, saved settings, custom agents and scripts that select gpt-5.5.

GPT-5.4 and GPT-5.4 mini retired from Codex

gpt-5.4 and gpt-5.4-mini retired from Codex with ChatGPT sign-in on August 31, 2026. The Codex models page now lists gpt-6-sol and gpt-6-luna as replacements.

Who is affected:

Codex users signed in with ChatGPT.

Action needed:

Replace gpt-5.4 with gpt-6-sol and gpt-5.4-mini with gpt-6-luna.

GPT-5.4 and GPT-5.4 mini leave Codex on August 31

GPT-5.4 and GPT-5.4 mini will no longer be available in Codex for ChatGPT sign-in from August 31, 2026. They stay on the API. Replacements named were GPT-5.6 Terra and GPT-5.6 Luna.

Who is affected:

Codex users signed in with ChatGPT who use GPT-5.4 or GPT-5.4 mini.

Action needed:

Update workspace defaults, saved settings and scheduled tasks before August 31.

GPT-5.3-Codex and GPT-5.2 deprecated in Codex

GPT-5.3-Codex and GPT-5.2 are no longer user-selectable in Codex for ChatGPT sign-in. API-key workflows are not affected.

Who is affected:

Codex users signed in with ChatGPT who used these models.

Action needed:

Switch to GPT-5.5, GPT-5.4 or GPT-5.4 mini.

Codex drops GPT-5.2-Codex, GPT-5.1-Codex models and GPT-5 for ChatGPT sign-in

From April 7 the Codex model picker stopped showing gpt-5.2-codex, gpt-5.1-codex-mini, gpt-5.1-codex-max, gpt-5.1-codex, gpt-5.1 and gpt-5, and they were removed for ChatGPT sign-in on April 14.

Who is affected:

Codex users signed in with ChatGPT who selected these models.

Action needed:

Switch to gpt-5.4 or another listed model, or use an API key.