Artificial Intelligence (AI) tools are evolving rapidly, and OpenAI is at the forefront with its powerful language models. As of June 2025, OpenAI offers two major model families: the GPT series and the newer o series.
OpenAI recently announced the o3 Pro model, adding even more advanced reasoning capabilities to the O series lineup. For many people, these names and version numbers can be confusing. What is the difference between GPT-4o and O3 Pro? When should you use GPT-4 Turbo versus O4 Mini?
This guide will explain these models clearly, so you can understand what they do and how they might be useful in your work or daily life.
Key Takeaways
- OpenAI has two model families: GPT models for language and multi-modal tasks, and O series models for advanced reasoning and tool use.
- GPT-4o is the flagship multi-modal model, it can understand text, images, and even audio.
- O3 and O3 Pro are the best choices for complex problem-solving and reasoning.
- Your access to these models depends on the ChatGPT plan you use. Free, Plus, Pro, Team, or Enterprise.
The Two Model Families Explained
GPT Models
GPT stands for Generative Pre-trained Transformer. These models are built to understand and generate human-like text, and the latest versions also handle images and audio.
- GPT-3.5: Fast and affordable, great for general text tasks.
- GPT-4 and GPT-4 Turbo: More advanced, with improved accuracy and the ability to handle longer conversations and documents.
- GPT-4o (“o” for omni): OpenAI’s latest flagship model. It can process text, images, and audio, making it ideal for multi-modal tasks.
- GPT-4.5: A research preview model, optimized for fewer mistakes in text generation.
O Series Models
The O series is designed for tasks that require advanced reasoning, problem-solving, and the use of external tools.
- O1 and O1 Pro: Strong at reasoning with text and using tools (like web browsers or code interpreters).
- O3 and O3 Pro: The latest and most capable models for complex reasoning. They can also handle multi-modal inputs (images, tables, and Python code).
- O4 Mini: A lighter, faster version of the O series that still supports multi-modal interactions.
Model Comparison Highlights
| Model | Best For | Multi-modal Support | Speed | Pricing (approx.) |
|---|---|---|---|---|
| GPT-4o | General use, creative tasks, multi-modal | Full (text, image, audio) | Very fast | Half the cost of GPT-4 Turbo |
| GPT-4.5 | Code generation, accurate text | Text only | Slightly slower | Research preview |
| O3 / O3 Pro | Advanced reasoning, tool use, complex analysis | Full multi-modal | Slower | $200/month for Pro |
| O4 Mini | Lightweight reasoning and multi-modal tasks | Multi-modal | Very fast | Cheaper than GPT-3.5 Turbo |
Which Model Should You Use?
For Individuals
- Everyday tasks (summarizing, writing, translating): GPT-4o Mini (Default on Free).
- Creative writing or professional content: GPT-4o (Plus plan).
- Understanding images or audio: GPT-4o.
For Developers & Professionals
- Coding and debugging: GPT-4.1, GPT-4.5, O3.
- Complex data analysis: O3 or O3 Pro.
- Building chatbots or summarizing documents: GPT-4 Turbo, GPT-4o, O4 Mini.
For Enterprise Users
- Team collaboration with privacy: ChatGPT Team plan (GPT-4o and O3 models included).
- Advanced AI with customization: ChatGPT Enterprise.
- Large-scale document processing: O3 and O4 Mini via the API.
How ChatGPT Plans Map to the Models
| Plan | GPT-4o (multi-modal) | GPT-4.5 (text only) | GPT-4 Turbo (text & vision) | GPT-4.1 (code) | GPT-3.5 Turbo (text only) | O3 / O3 Pro (advanced reasoning) | O1 / O1 Pro / O4 Mini |
| Free | Limited (capped) | Not available | Not available | Not available | Default model | Not available | Not available |
| ChatGPT Plus ($20) | Capped (~80/3hr) | Available (preview) | Available | Available (limited) | Available | O3 available | O1, O4 Mini available |
| ChatGPT Team | Higher cap | Available | Available | Available | Available | O3 available | O1, O4 Mini available |
| ChatGPT Pro ($200) | Nearly unlimited | Unlimited preview | Available | Available | Available | O3 Pro available | O1 Pro, O4 Mini available |
| ChatGPT Enterprise | Unlimited | API & internal use | Available | Available | Available | O3 Pro available | O1 Pro, O4 Mini available |
Why This Matters
AI models are becoming part of everyday life, not just for developers, but for students, professionals, and businesses of all sizes. Understanding the difference between OpenAI’s GPT and O series models helps you:
- Choose the right tool for your task
- Understand pricing and speed differences
- Take advantage of new multi-modal features
If you want an assistant that can look at images or listen to voice commands, GPT-4o is a great choice. If your work involves analyzing complex data or building reasoning-based applications, O3 or O3 Pro may be better.
Final Thoughts
The landscape of AI models continues to evolve. OpenAI’s GPT series models remain the go-to choice for general language tasks and multi-modal interactions. Meanwhile, the O series is pushing the boundaries of what’s possible in reasoning and tool-based problem-solving.
As more tools and apps start using these models behind the scenes, understanding their strengths will help you stay ahead. Whether you’re using ChatGPT casually or integrating AI into your business.
Stay tuned, the next generation of AI assistants is already here, and it’s getting smarter every month.
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