Word spread quickly across the machine learning and AI community on the social network X yesterday: OpenAI was sending developers an email notifying them that the company would be removing one of its largest and most powerful large language models (LLMs), GPT-4.5 Preview, from the official OpenAI application programming interface (API) on July 14, 2025.

However, as an OpenAI spokesperson told VentureBeat via email, GPT-4.5 Preview will remain an option to individual ChatGPT users through the dropdown model selector menu at the top of the application.

But it stil means that any third-party developers who had built applications or workflows atop GPT-4.5 preview (we’ll call it GPT-4.5 from here on out for simplicity’s sake, since a full GPT-4.5 was never made available on this platform), now need to switch over to another one of OpenAI’s nearly 40 (!!!) different model offerings still available through the API.

The news quickly spread on X, where developers and AI enthusiasts posted reactions ranging from disappointment to confusion.

Some described GPT-4.5 as a daily tool in their workflow, praising its tone and reliability. Others questioned the rationale behind launching the model in the first place if it was going to be short-lived.

“This is sad — GPT-4.5 is one of my fav models,” wrote @BumrahBachi.

Ben Hyak, the co-founder of AI observability and performance monitoring platform Raindrop.AI, called the move “tragic,” adding: “o3 + 4.5 are the models I use the most everyday.”

Another user, @flowersslop asked bluntly, “what was the purpose of this model all along?”

Deprecation had been planned since April

Despite the strong reaction, OpenAI had in fact already announced the plan to deprecate GPT-4.5 Preview back in April 2025 during the launch of GPT-4.1.

At that time, the company stated that developers would have three months to transition away from 4.5. OpenAI framed the model as an experimental offering that provided insights for future development, and said it would carry forward learnings from GPT-4.5 into future iterations — particularly in areas like creativity and writing nuance.

In a follow-up response to VentureBeat, OpenAI communications confirmed that the June email was simply a scheduled reminder and that there are currently no plans to remove GPT-4.5 from ChatGPT subscriptions, where the model remains available.

Community speculation on cost and model strategy

Still, the developer-facing deprecation leaves a gap for some users, especially those who had built workflows or products around GPT-4.5’s specific characteristics.

Some in the community speculated that high compute costs might have influenced the move, noting that similar changes had occurred with prior models.

Others referenced recent API pricing updates, including a major reduction in cost for GPT-3.5 (internally referred to as o3), which is now priced 80% lower than before.

User @chatgpt21 commented that GPT-4.5 is the “best non reasoning model for open ai on all benchmarks and it’s obvious,” and predicted that OpenAI will “they add test time compute it will blow o3 out of the water. In order to scale TTC you need to scale pre training”

The end of the road for GPT-4.5 via API — developers encouraged to migrate to GPT-4.1

OpenAI has directed developers to its online forum for questions about migrating to GPT-4.1 or other models. With the API shutdown for GPT-4.5 Preview set for mid-July, teams relying on the model now have less than a month to complete that transition.