GPT-4.5 vs GPT-4o: Comparing OpenAI’s Latest AI Models

(OpenAI)

OpenAI’s GPT-4.5 and GPT-4o are two advanced generative AI models that build on the success of GPT-4. Although they share a common lineage, these models have distinct focuses and strengths. GPT-4o (with “o” for “omni”) was introduced in mid-2024 as a multimodal model integrating text, vision, and audio capabilities. GPT-4.5 followed in early 2025, just a few weeks ago, as a scaled-up language model aimed at greater knowledge and conversational intelligence.

Below I compare their key features, performance in tasks like writing and coding, user-reported pros and cons, and how they’re being received in real-world use.

Table Comparison

To understand the differences, here’s a side-by-side look at GPT-4.5 and GPT-4o:

(Table: A comparison of OpenAI’s GPT-4o and GPT-4.5 models.)

Performance in Writing, Coding, and Reasoning

GPT-4.5 (green) significantly improves factual answer accuracy (left) and reduces hallucinations (right) compared to GPT-4o. (OpenAI)

When it comes to language and writing tasks, GPT-4.5 has a clear edge in creativity and nuance. OpenAI describes GPT-4.5 as having a more “thoughtful personality” that excels at creative writing and natural conversation.

In one test carried out by techradar, GPT-4.5’s answers often feel more human-like and context-aware. For example, one side-by-side test found both models answered a movie trivia question correctly, but GPT-4.5 gave a smooth, explanatory response in plain paragraphs, whereas GPT-4o’s answer was formatted as an odd list — technically correct but less natural to real.

(techradar)

This reflects GPT-4.5’s higher emotional intelligence and ability to pick up subtle cues. In fact, early users report GPT-4.5 is better at sensing tone or unstated preferences in a prompt, like giving a simpler recipe when someone says they’re “bored of pasta.” It tends to “recognize the unstated preferences”…