OpenAI is retiring GPT-5.5 from ChatGPT, ChatGPT Work and Codex on Wednesday, ending a run of barely six months for the model. The company told users to migrate to newer systems, continuing a brisk cycle of model deprecations that has defined its product strategy through 2026.
What changes today
Starting October 14, GPT-5.5 will no longer be available in ChatGPT, ChatGPT Work or Codex when accessed through plan-based authentication, according to OpenAI's documentation. The company announced the date on September 15 through the ChatGPT account on X, telling Codex users to switch to GPT-5.6 Sol or GPT-6 Astra. Developers who access the model through the OpenAI API are unaffected and can continue using it.
Why developers should care
The retirement matters most for teams that built workflows around the model. Codex users who sign in with ChatGPT are told to move from gpt-5.5 to gpt-5.6-sol and to check workspace defaults, saved model settings, custom agents, scheduled tasks and scripts that still name the old model. Requests that name GPT-5.5 directly will fail rather than fall back gracefully, the same failure mode developers hit when earlier models were cut. For everyday ChatGPT users, the shift should be seamless as conversations move to whichever model OpenAI designates as the default.
A familiar pattern
The retirement fits a rhythm OpenAI has settled into this year. GPT-5.4 and GPT-5.4 mini were retired from Codex at the end of August in what was the third deprecation wave of 2026, following an earlier sunset in June and a cleanup of legacy models in April. GPT-5.5 itself shipped only on April 23, meaning it is being withdrawn before its seventh month. GPT-4.5 left ChatGPT in June with its conversations handed to GPT-5.5, and GPT-5.5 is now getting the same treatment as GPT-6 Astra, OpenAI's current flagship, takes centre stage.
Sources: OpenAI to retire GPT 5.5 from ChatGPT, Work and Codex on October 14 | OpenAI to discontinue GPT-5.5 on October 14
What changes today
Starting October 14, GPT-5.5 will no longer be available in ChatGPT, ChatGPT Work or Codex when accessed through plan-based authentication, according to OpenAI's documentation. The company announced the date on September 15 through the ChatGPT account on X, telling Codex users to switch to GPT-5.6 Sol or GPT-6 Astra. Developers who access the model through the OpenAI API are unaffected and can continue using it.
Why developers should care
The retirement matters most for teams that built workflows around the model. Codex users who sign in with ChatGPT are told to move from gpt-5.5 to gpt-5.6-sol and to check workspace defaults, saved model settings, custom agents, scheduled tasks and scripts that still name the old model. Requests that name GPT-5.5 directly will fail rather than fall back gracefully, the same failure mode developers hit when earlier models were cut. For everyday ChatGPT users, the shift should be seamless as conversations move to whichever model OpenAI designates as the default.
A familiar pattern
The retirement fits a rhythm OpenAI has settled into this year. GPT-5.4 and GPT-5.4 mini were retired from Codex at the end of August in what was the third deprecation wave of 2026, following an earlier sunset in June and a cleanup of legacy models in April. GPT-5.5 itself shipped only on April 23, meaning it is being withdrawn before its seventh month. GPT-4.5 left ChatGPT in June with its conversations handed to GPT-5.5, and GPT-5.5 is now getting the same treatment as GPT-6 Astra, OpenAI's current flagship, takes centre stage.
Sources: OpenAI to retire GPT 5.5 from ChatGPT, Work and Codex on October 14 | OpenAI to discontinue GPT-5.5 on October 14
