How to Use Different OpenAI ChatGPT Models in 2025 - The comprhensive Analysis & Test

At University 365, where the future of lifelong learning is shaped by the fusion of neuroscience and artificial intelligence, understanding the latest AI tools is not just an advantage—it’s a necessity.

As AI continues to revolutionize the way we work, communicate, and create, mastering the diverse range of OpenAI’s ChatGPT models in 2025 becomes essential for students, professionals, and entrepreneurs alike. This publication delves into the unique capabilities of each OpenAI model, guiding you on when and how to use them effectively in your personal and professional life.

From the fastest, most efficient models designed for everyday quick tasks to the most advanced, agentic AI capable of deep research and complex reasoning, we explore the strengths and ideal applications of the GPT-4 Mini, GPT-4o, GPT-4.5, 03, and 04 series.

This comprehensive analysis is crafted to help you harness AI’s potential to become a superhuman generalist—equipped with versatile AI skills that University 365 champions as the key to thriving in an AI-driven job market.

GPT-4 Mini: The Fast and Efficient Everyday Assistant

The GPT-4 Mini model stands out as the smallest and fastest member of OpenAI’s GPT-4 family, designed specifically for quick, everyday tasks that require minimal deep reasoning. This model is a compact, cost-efficient version of GPT-4, delivering powerful AI capabilities while significantly reducing computational cost and latency.

One of the key advantages of GPT-4 Mini is its near unlimited availability without the risk of rate limiting, allowing users to engage with it continuously throughout the day. This makes it ideal for integrating into chatbots and virtual assistants that handle large volumes of customer queries in real time, where speed and responsiveness are critical.

Examples of suitable everyday queries include simple factual questions like, “Do eggs in the UK need to be refrigerated?” GPT-4 Mini can often access the internet to quickly find relevant information, making it highly useful for fast fact-checking and decision-making nudges in daily life.

However, GPT-4 Mini is not designed for tasks requiring complex reasoning or lengthy responses. For instance, if you need a detailed recipe or in-depth explanations, this model might not be the best choice. While it supports image inputs, it is generally recommended to avoid them since the model’s primary strength lies in delivering rapid text responses.

GPT-4o: The Versatile All-Rounder With Vision, Image generation, and Voice

Moving beyond the mini version, GPT-4o is a generalist model that excels at a wide variety of tasks without specializing in any one area. This all-round chatbot is perfect for users who want a reliable AI companion to assist with writing essays, creating video scripts, generating emails, and even translating text at blistering speeds.

One of the standout features of GPT-4o is its ability to format responses in a visually appealing and easy-to-digest manner. For example, when asked to write a video script explaining quantum computing to 10-year-olds, GPT-4o generates structured content with clear sections such as the host’s dialogue and on-screen visuals.

This makes it an excellent tool for content creators and communicators who require clarity and engagement.

GPT-4o also shines as a conversationalist, ideal for brainstorming ideas or having back-and-forth discussions. Its proficiency in generating detailed, well-thought-out emails makes it especially useful in professional settings, such as drafting a resignation letter or business correspondence.

Beyond text, GPT-4o boasts impressive multimodal capabilities, able to analyze and explain images effectively. While not the top model for vision tasks, it is sufficient for quick image dissection to understand visual content. This model also forms the foundation for OpenAI’s voice mode, enabling users to interact with the AI using speech, which is particularly handy when multitasking or when typing is inconvenient.

With internet access integrated, GPT-4o can fetch real-time information, such as the latest sports results or current events, enhancing its utility as an AI assistant that keeps you informed on the go.

GPT-4.5: The Creative and Emotionally Intelligent Writer

GPT-4.5 represents a leap forward in emotional intelligence and creative writing. This model adapts its tone and language to the context of the conversation, producing responses that feel more natural, empathetic, and polished. Such attributes make GPT-4.5 exceptionally well-suited for drafting persuasive emails, professional communications, and social media posts that require a human touch.

While GPT-4.5 is slower than other models, the quality of its output compensates for the extra time. It excels in creative writing tasks where subtlety and nuance matter, such as storytelling or crafting texts that invoke emotional resonance. Tests have shown GPT-4.5 to be almost twice as impressive as GPT-4 in mimicking human-like responses and understanding complex emotional cues.

Another significant advantage of GPT-4.5 is its reduced tendency for hallucinations, meaning it provides more accurate and factually reliable answers. This makes it a dependable choice when accuracy is critical, alongside the need for a conversational tone that resonates with human readers.

Moreover, GPT-4.5’s enhanced understanding of human emotions allows it to offer insightful advice and empathetic responses, which can be valuable for users seeking thoughtful reflection or guidance, although it should not replace professional therapy or counseling.

o3: The Agentic AI Powerhouse for Complex Tasks

Among the models, o3 stands as the most powerful and sophisticated AI agent. Unlike traditional chatbots, o3 operates as an AI agent wrapped within a conversational interface, capable of undertaking complex tasks autonomously. It can conduct deep research, generate detailed reports, create graphs, and integrate multiple tools to solve intricate problems.

One of the most remarkable capabilities of o3 is its advanced image analysis. Unlike simpler models that perform basic visual classification, o3 can zoom in, crop, and scrutinize minute details within an image. It then cross-references this information with internet sources to provide highly accurate identifications and contextual understanding.

For example, when tasked with guessing the location of a vague image from the game GeoGuessr, o3 meticulously examines parts of the image, researches online, and confirms details to pinpoint the location with extraordinary accuracy.

This level of granularity is unprecedented and invaluable for tasks requiring real-world contextual understanding.

Beyond vision, o3 excels in advanced business analysis. Thanks to its internet browsing capabilities and tool integrations, it can analyze business data, generate visualizations, and forecast insights with remarkable precision. This makes o3 an indispensable tool for entrepreneurs, analysts, and researchers who need comprehensive and grounded AI assistance.

Its ability to reason through complex STEM problems and utilize external tools sets 03 apart as the go-to model for sophisticated applications where accuracy, depth, and multi-step thinking are paramount.

o4 Series: The Math Specialists

The 04 models, including o4 Mini and 04 Mini High, are tailored specifically for mathematical problem-solving. These models excel at tackling complex calculations, business forecasting, and any task that requires rigorous numerical reasoning.

While not every user will need advanced math capabilities daily, those who do will find o4 indispensable. For instance, if you need to calculate net profit over multiple periods or analyze financial data, o4 can process spreadsheet inputs and reason through the numbers to provide accurate and insightful solutions.

OpenAI has trained these models using reinforcement learning to ensure they pursue logical chains of thought, making them highly reliable for solving difficult mathematical prompts. This specialization makes 04 the best choice for users with math-intensive use cases, such as business owners, data scientists, and financial analysts.

Deep Research vs. o3: Choosing the Right Tool for In-Depth Analysis

OpenAI offers two closely related options for deep research: the deep research tool and the 03 model. Both are designed to generate comprehensive research reports, but they differ in approach and speed.

Deep research focuses on quickly gathering information to produce a research report, ideal for writing essays or obtaining a broad overview. However, it can take between 5 to 15 minutes to complete a report and typically allows more queries.

In contrast, 03 provides an agentic solution that not only researches but also organizes data, creates tables, and applies problem-solving logic. It is faster, often delivering answers in under 3 minutes, but usage is limited to around 50 to 100 queries per week due to its computational intensity.

Users should choose deep research when they need more frequent queries for broad research and 03 when they require detailed, tool-assisted analysis and faster turnaround for complex problems.

Conclusion: Embracing AI Versatility with University 365

Understanding the distinct strengths and optimal use cases of OpenAI’s ChatGPT models in 2025 equips learners and professionals with the tools to navigate an AI-augmented future confidently. Whether you require rapid answers from GPT-4 Mini, versatile assistance from GPT-4o, emotionally intelligent communication from GPT-4.5, the agentic power of 03, or the mathematical prowess of the 04 series, mastering these models empowers you to become a superhuman AI generalist.

University 365 remains committed to guiding its community through these technological advances by integrating AI literacy into its holistic educational approach. Staying updated with the latest AI innovations ensures that our students, faculty, and alumni remain indispensable contributors to the evolving job market shaped by AI agents, AGI, and beyond.

By embracing the diverse capabilities of OpenAI’s ChatGPT models, you position yourself at the forefront of AI-driven success—ready to adapt, innovate, and excel in a rapidly changing world.