OpenAI Retires GPT-5.5 From ChatGPT and Codex

OpenAI removed GPT-5.5 from ChatGPT, ChatGPT Work, and Codex on Wednesday, Oct. 14, less than six months after the model’s April 23, 2026 launch. The change applies to consumer, Business, Enterprise, and Edu plans.

The OpenAI API is not part of this retirement. Developers who directly call GPT-5.5 through the API can continue using it for now.

GPT-5.5 Is Replaced by Newer GPT-6 Models

OpenAI is directing paid users toward newer GPT-6 models, with GPT-6.1 Sol positioned for agentic coding. GPT-5.5 was surpassed roughly 11 weeks after launch when the GPT-5.6 family arrived in July, including Sol, Terra, and Luna.

Codex documentation initially instructed users to replace gpt-5.5 with gpt-5.6-sol before the retirement deadline. Since then, OpenAI has released two newer generations of Sol.

For users of ChatGPT, ChatGPT Work, and Codex, GPT-5.5 is no longer available as a selectable model. API access remains unchanged at this time.

GPT-6.1 Sol Availability and Pricing

OpenAI released GPT-6.1 Sol on Sept. 29 as an update to GPT-6 Sol. The company says GPT-6.1 Sol nearly matches GPT-6 Astra’s intelligence for agentic coding, computer use, and professional work while using one-fifth of Astra’s standard input and output token prices.

GPT-6.1 Sol API pricing is:

Paid ChatGPT users can select GPT-6.1 Sol in Codex and ChatGPT Work. It is not yet available in regular ChatGPT.

OpenAI also began rolling out an “Ultrafast” tier in early October. The company says this tier can generate tokens up to eight times faster.

GPT-6.1 Sol Safety Findings

According to OpenAI’s system card addendum, GPT-6.1 Sol generated 56% fewer high-severity misalignment flags than GPT-5.6 Sol in simulated internal Codex traffic.

That figure comes from simulated internal traffic and specifically compares GPT-6.1 Sol with GPT-5.6 Sol in the Codex setting.

ChatGPT Referral Tracking May Have Changed

Separately, Search Engine Roundtable reported that ChatGPT appears to have stopped attaching UTM tracking parameters to outbound links. The reported change makes it more difficult for publishers to identify visits originating from ChatGPT.

The outlet said the behavior appeared to begin with the GPT-6 release, around a week before its report. OpenAI had added UTM tracking parameters to ChatGPT links in June.

Cedric Huesler of Adobe examined roughly 500 pages where ChatGPT represented at least 5% of visits. He compared Oct. 9–13 with the prior week. According to the report, visits attributed to ChatGPT fell by about 31,000 per day, while direct visits to those same pages rose by about 26,000 per day.

Search Engine Roundtable said it was unclear whether the change was intentional. OpenAI has not publicly commented on the reported removal of tracking parameters.

FAQ

Has OpenAI removed GPT-5.5 from the API?

No. GPT-5.5 remains available for developers who call the model directly through the OpenAI API, at least for now. The retirement applies to ChatGPT, ChatGPT Work, and Codex.

Which users are affected by the GPT-5.5 retirement?

The change affects consumer, Business, Enterprise, and Edu plans. Paid users are being directed toward newer GPT-6 models.

Can users select GPT-6.1 Sol in regular ChatGPT?

No. Paid users can select GPT-6.1 Sol in Codex and ChatGPT Work, but it is not yet available in regular ChatGPT.