GPT-4.5 and GPT-5: Opening AI Models for Writing, Programming, and Problem-solving in a Deep Search Environment

We revealed in Notepad last week that OpenAI was planning to launch GPT-4.5 by the end of February, and GPT-5 as soon as late May. OpenAI CEO Sam Altman has referred to GPT-5 as a “system that integrates a lot of our technology,” and it will include OpenAI’s new o3 reasoning model, which the company teased during its 12 days of Christmas announcements in December.

GPT-4.5 will have better writing capabilities, improved world knowledge, and what OpenAI calls a “refined personality over previous models.” The model of GPT 4.5 is better at recognizing patterns and drawing connections which makes it an ideal model for writing, programming, and problem-solving.

There will not be enough new capabilities to make it a frontier model. “GPT-4.5 is not a frontier model, but it is OpenAI’s largest LLM, improving on GPT-4’s computational efficiency by more than 10x,” OpenAI said in a document that leaked ahead of its announcement. It does not introduce any net-new frontier capabilities compared to previous releases and its performance is less than that of o1, and deep research on most readiness evaluations. OpenAI has since removed this mention from an updated version of the document.

So, what’s it like to use the new model? Pro users are getting a first look, with rollouts for Plus and Team users scheduled for next week and Enterprise and Edu the week afterwards. GPT-4.5 supports the web search and canvas feature as well as uploads of files and images, though it’s not yet compatible with the AI Voice Mode.

DeepSeeks R1 was one of the innovations that attempted to match the performance of a frontier model with as little resources as possible. Through scaling it models, OpenAI still sees a strong path forward. The researchers that worked on GPT-4.5 stated that the kind of maximalist mindset to model development has captured more nuances of human emotions and interactions.

Prior to this launch, 2025 has already been filled with new AI model releases. Anthropic created a hybrid reasoning model for Claude. The Chinese researchers at DeepSeek released a model on a small budget, prompting OpenAI to drop a mini model a month ago.