OpenAI to retire GPT-5.5 from ChatGPT and Codex on Oct. 14

OpenAI announced on September 15 that it will remove GPT-5.5 from ChatGPT, ChatGPT Work, and Codex on October 14, giving developers and users roughly a month to migrate their workflows to newer models. The retirement applies across all subscription tiers, including consumer, Business, Enterprise, and Edu plans.moneycontrol+2

"On October 14, it's time to say farewell to GPT-5.5 in ChatGPT, ChatGPT Work, and Codex across all plans," the official ChatGPT account posted on X. "If you use GPT-5.5 in Codex, switch to GPT-5.6 Sol or GPT-6 Astra."x+1

What Changes — and What Doesn't

The October 14 deadline is a product-surface retirement, not a full model shutdown. GPT-5.5 will remain available through the OpenAI API, and Codex sessions authenticated with an API key rather than a ChatGPT login are unaffected. Developers who call the model server-side through the API have no immediate migration deadline.startupfortune+2

For everyone else, any request that names GPT-5.5 directly after October 14 will return an error. That means developers with the model hardcoded into workspace defaults, custom agent configurations, or Codex CLI scripts will need to update those references before the cutoff.startupfortune

Replacement Models

OpenAI is directing users to two successor models: GPT-5.6 Sol, positioned for coding and agentic workloads, and GPT-6 Astra, the company's newer flagship with broader capabilities spanning browsing, software engineering, and cybersecurity. Codex documentation specifically instructs users to replace gpt-5.5 with gpt-5.6-sol.orcarouter+3

GPT-5.5 launched on April 23, 2026, meaning it will have been available in ChatGPT for less than six months before its removal. The timeline follows a pattern of rapid model turnover throughout 2026: GPT-5.2 and GPT-5.3-Codex were cut from ChatGPT in June, and GPT-5.4 was retired from Codex at the end of August.aibusinessweekly+1

A Tighter Development Cycle

The pace of retirements has drawn frustration from developers on OpenAI's community forums, some of whom had asked the company to keep GPT-5.5 as a legacy option in Codex. OpenAI declined. While the company's stated policy promises six months of notice for generally available models, teams that adopted GPT-5.5 weeks after launch say the practical window feels considerably shorter. As one migration guide noted, "the pattern: everything funnels into the GPT-5.6 family."developersdigest+1