GPT 4o vs GPT 4.5 – What’s the Difference?

• Michael Willson
• March 20, 2025

AI is moving faster than ever, and GPT-4.5’s rushed release proves just how competitive the space has become. OpenAI originally planned to introduce GPT-5 later in 2025, but something unexpected happened: China’s DeepSeek and Musks’s Grok 3 from xAI entered the scene. These models gained massive traction, shaking up the industry. The stock market reacted instantly, with NVIDIA, Microsoft, and OpenAI seeing sudden losses.

To stay ahead, OpenAI made a surprise move and launched GPT-4.5 much earlier than expected. But was this a necessary upgrade or just a quick response to market pressure? How does it compare to GPT-4o?

Let’s understand the differences between GPT-4o and GPT-4.5.

What Are GPT-4o and GPT-4.5?

AI models like GPT-4o and GPT-4.5 are part of OpenAI’s Generative Pre-trained Transformer (GPT) series. These systems generate human-like text and assist with tasks like writing, coding, problem-solving, and conversation.

GPT-4o, released in 2024, introduced a multimodal approach, meaning it can handle text, images, and audio. It was designed for speed, affordability, and real-time interactions.

GPT-4.5, launched in February 2025, arrived unexpectedly after DeepSeek and Grok 3 gained traction. It wasn’t the major leap users expected from GPT-5, but it still brought better reasoning, improved accuracy, and fewer hallucinations. However, it demands more computing power and costs more than its predecessor.

Understanding the differences between GPT-4o and GPT-4.5 can help you decide which one fits your requirements. If you’re diving into the latest AI models, getting the Certified Artificial Intelligence (AI) Expert™ certification can help you stay ahead.

When Was GPT-4o Released and What Does It Offer?

GPT-4o debuted in May 2024, bringing a fast, multimodal AI solution to the market. Its biggest strength is its ability to process text, images, and audio, making it more versatile than earlier models.

What Are the Key Features of GPT-4o?

• Multimodal Capabilities – Unlike previous models, GPT-4o understands and generates text, images, and audio.
• Fast Processing Speeds – Optimized for real-time responses, making it perfect for chatbots and instant translations.
• Cost-Effective – More affordable than many AI models, making it a better choice for startups and small businesses.

Who Should Use GPT-4o?

GPT-4o is ideal for:

• Real-time applications, such as customer support chatbots and virtual assistants.
• Users working with multimedia, requiring AI to analyze text, images, and audio together.
• Businesses looking for an affordable AI solution without sacrificing performance.

How Is GPT-4.5 Different and Why Was It Released So Soon?

GPT-4.5 wasn’t originally in OpenAI’s roadmap, it was supposed to jump straight to GPT-5 in late 2025. But when DeepSeek and Grok 3 gained market share, OpenAI had to act fast.

Instead of waiting for a full-fledged upgrade, they introduced GPT-4.5 in February 2025. It didn’t bring a huge leap in AI capabilities but focused on better reasoning, accuracy, and conversation flow.

What Are the Key Improvements in GPT-4.5?

• Stronger Logical Thinking – Handles multi-step tasks better than GPT-4o.
• Fewer AI Hallucinations – Generates more reliable responses with fewer inaccuracies.
• More Natural Conversations – Maintains context longer in extended discussions.

Who Should Use GPT-4.5?

This model works best for:

• Researchers and professionals needing an AI with better accuracy and reasoning skills.
• Writers and content creators who want natural, engaging text generation.
• Developers and businesses that need more advanced AI processing despite higher costs.

What Are the Differences Between GPT-4o and GPT-4.5?

Which Model Has Better Reasoning?

If problem-solving and logical analysis are your priorities, GPT-4.5 is the better choice. It handles complex, multi-step tasks better than GPT-4o, making it suitable for legal research, finance, and data science.

How Do They Compare in Creativity?

GPT-4.5 delivers more engaging, human-like responses, making it better for storytelling, blog writing, and creative projects. Meanwhile, GPT-4o is optimized for speed, making it ideal for shorter, direct responses.

Which Model Supports More Data Types?

GPT-4o has the upper hand in multimodal processing, as it can handle text, images, and audio. GPT-4.5 focuses mainly on text, making it less versatile for tasks requiring multimedia.

Which One Works Faster?

If speed is your priority, GPT-4o is the clear winner. It delivers responses faster than GPT-4.5, making it the best option for real-time AI applications like customer service chatbots.

How Do GPT-4o and GPT-4.5 Compare in Benchmarks?

In March 2025, OpenAI released benchmark test results comparing GPT-4o and GPT-4.5:

• Problem-solving: GPT-4.5 scored 92% on logic-based tasks, while GPT-4o achieved 88%.
• Mathematical reasoning: GPT-4.5 showed a 4% improvement over GPT-4o in complex math problems.
• Conversational retention: GPT-4.5 maintained context up to 15 dialogue turns, while GPT-4o started losing track after 10 exchanges.

These differences prove that while GPT-4.5 refines AI reasoning, the improvements are incremental rather than groundbreaking. Understanding AI models deeply can make you a better Certified Artificial Intelligence (AI) Developer™.

What Happened in the February 2025 Demo?

During a live demonstration in February 2025, OpenAI showcased GPT-4.5’s enhanced performance.

• Image analysis test: GPT-4.5 identified not just a dog in a park but its breed and background details. GPT-4o only provided a general description.
• Speech recognition: GPT-4.5 successfully transcribed a Scottish accent, which GPT-4o struggled with.
• Translation test: GPT-4.5 handled French slang better than GPT-4o, which gave a more rigid translation.

This demo confirmed that GPT-4.5 had better accuracy but wasn’t drastically more advanced than GPT-4o.

How Do Their Costs Compare?

There’s a huge price gap between these two models:

• GPT-4o – $2.50 per million input tokens, $10 per million output tokens
• GPT-4.5 – $75 per million input tokens, $150 per million output tokens

If you’re using AI on a large scale, GPT-4o is far more budget-friendly. GPT-4.5 costs more due to its advanced reasoning abilities.

Which Model Should You Choose?

When Is GPT-4o a Better Option?

GPT-4o is the best choice if:

• You need an AI for real-time applications like chatbots or voice assistants.
• Your work involves processing multiple data types, including text, images, and audio.
• You’re looking for an affordable AI model that balances performance and cost.

When Should You Use GPT-4.5?

GPT-4.5 is ideal if:

• You need high accuracy and strong problem-solving capabilities.
• Your work requires long-form AI interactions, such as research, writing, or in-depth conversations.
• You don’t mind paying extra for better AI performance.

What’s Next for OpenAI’s GPT Models?

GPT-4.5 was never meant to exist, OpenAI was originally focused on GPT-5. But market competition forced an early release. Now, all eyes are on what’s next.

GPT-5 is rumored to arrive later in 2025, bringing more efficiency and human-like responses. OpenAI has hinted at lower energy consumption, better ethical safeguards, and even more advanced reasoning.

For now, GPT-4o and GPT-4.5 serve different user needs. If you need fast, affordable, and multimodal AI, go for GPT-4o. If you need higher precision, deeper reasoning, and don’t mind the extra cost, GPT-4.5 is the way to go.

Understanding the differences between GPT-4o and GPT-4.5 helps you make the right decision based on your needs, budget, and future plans.