Last Updated on April 14, 2025 by Michael Motha
OpenAI has announced its phasing out GPT-4.5 from its developer API in favor of its new GPT-4.1 model. When it launched, OpenAI described GPT-4.5 as its best and most capable model so far, in part because it was a more natural conversationalist and could capably mimic some notion of emotional intelligence. Despite what its name suggests, GPT-4.1 is supposed to be better and more efficient.
OpenAI says GPT-4.1 is available exclusively to developer’s using OpenAI’s API, and comes in three sizes, GPT-4.1, GPT-4.1 mini and GPT-4.1 nano. That means that if you won’t find it as in option in the public-facing ChatGPT interface, but you could someday interact with an agent that leverages the model’s improvements. GPT-4.1 is supposed to be better at coding and “long context understanding,” according to OpenAI, with support for “up to one million tokens of context” and knowledge of the world up to June 2024.
Important to the decision to phase out the GPT-4.5 Preview, GPT-4.1 is also cheaper to run. OpenAI says the model is “26 percent cheaper than GPT-4o for median queries.” The company imagines developers using GPT-4.1 to build agents that can work in software engineering environments, one of the more popular uses for generative AI. Even though GPT-4.5 will be eventually removed from OpenAI’s API, the model preview will still be available in ChatGPT if you wan’t to play with it.
OpenAI says the GPT-4.1 family is available to use today via the company’s API. GPT-4.5 will be fully-phased out in three months on July 14, 2025.
