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OpenAI removes GPT-4.5 from ChatGPT, completing the shift to the GPT-5 series

· by Pondero Newsdesk

The short version

GPT-4.5 was pulled from ChatGPT on June 27, 2026, after a 30-day sunset period. It was the last model in ChatGPT predating the GPT-5 series. The API is unaffected.

OpenAI removes GPT-4.5 from ChatGPT, completing the shift to the GPT-5 series

GPT-4.5 disappeared from ChatGPT on June 27, 2026. The removal closed a 30-day window that OpenAI opened on May 28, and left the consumer product running entirely on GPT-5-series models for the first time.

What happened

OpenAI announced the retirement on May 28, 2026, alongside a GPT-5.5 Instant quality update, per the company's own Model Release Notes. The notes cited "limited usage" as the rationale, stating the company is retiring older models "so we can better serve our newer, most capable models." GPT-4.5 had been restricted to paid users via the model picker, so the removal affects that tier only.

The change is ChatGPT-only. OpenAI said explicitly in the same release notes that there are "no changes to the API," so teams using GPT-4.5 programmatically via platform.openai.com can continue for now. A separate API deprecation timeline would be needed to change that.

GPT-4.5 launched as a research preview in February 2025 and was positioned as OpenAI's largest chat model at the time, emphasizing broad knowledge and conversational quality over structured reasoning. Its removal from ChatGPT means the consumer product no longer carries any model predating the GPT-5 lineage.

OpenAI has been accelerating this consolidation. GPT-4o, GPT-4.1, GPT-4.1 mini, and o4-mini were all retired from ChatGPT in February 2026, per the same release notes. GPT-5.1 models followed in March. GPT-4.5 is the latest in that sequence.

Why it matters

For users who had pinned GPT-4.5 in the model picker, June 27 was the hard cutoff. GPT-5.5 Instant is now the default conversational model in ChatGPT for most sessions, and the model notes describe it as more natural and better paced than its predecessor. Whether it covers the same ground as GPT-4.5 for any specific workflow depends on the task.

The API distinction is practical. Developers who depend on GPT-4.5 for production pipelines have no immediate action required. OpenAI has not set an API removal date as of this writing. A ChatGPT removal has preceded an API sunset by several months in prior retirement cycles, so teams building on gpt-4.5-preview should begin planning a migration path.

OpenAI o3 is next in the queue. It is scheduled for removal from ChatGPT on August 26, 2026, after a 90-day sunset announced on the same May 28 date.

Context

The pace of GPT-4-era retirements from ChatGPT tracks with OpenAI's aggressive release schedule through 2025 and into 2026. Each retirement is framed around clearing compute headroom for newer models, though OpenAI has not published data on the compute savings from any specific model exit. The company's Model Release Notes are the authoritative source for deprecation schedules across both ChatGPT and the API.

What to watch next

Two things warrant tracking. The first is whether OpenAI sets an API retirement date for GPT-4.5 before the o3 ChatGPT exit on August 26. The second is how GPT-5.5 Instant performs for users who previously chose GPT-4.5 specifically for its EQ and creative writing strengths rather than reasoning. OpenAI has not published a direct capability comparison between the two.

Sources