A guide to all ChatGPT AI models: which one to choose and for what purpose

ChatGPT is more than just a chatbot. It’s an entire platform with multiple AI models, each suited for different tasks. The ChatGPT lineup is a real hodgepodge of names like GPT-4o, o3, o1 pro, o4-mini-high and others. Figuring out which model is right for you can be tricky, especially if you’re using the platform for work or business. This article will help you understand what models exist, what makes them different, who they are available to, and what situations are worth using each.

Free access: basic models for everyday tasks

GPT-4o -a versatile model for every day

GPT-4o is the main model used in the free version of ChatGPT. It was introduced in May 2024 and is considered the flagship among universal AI. Its main advantage is multimodality: it can handle text, images, audio and video.

• Generate and edit text
• Analyze documents
• Write letters, articles and reports
• Answer questions
• Recognize objects in pictures
• Recognize audio (e.g., recognize speech in a video of a meeting)
• Draw conclusions based on participants’ reactions (e.g., to a proposed idea)

This is a reliable, fast and stable model that is suitable for most everyday tasks – both work and personal.

Example: you missed a meeting and uploaded a video. GPT-4o can analyze it, determine how attendees reacted to your idea, and even suggest how best to develop it.

GPT-4o-mini -a lightweight and fast version

When you are using the free version of ChatGPT and the service is overloaded, the system can temporarily switch you to GPT-4o-mini. This model is faster and lighter, but less accurate. It can be compared to a “workhorse” for simple tasks:

• fast calculations
• writing drafts
• answering short questions
• repeated actions (e.g., generating product descriptions)

Available with ChatGPT Plus and Team subscription

GPT-4.5 -a model with increased emotional intelligence

GPT-4.5 emerged in February 2025 as an experimental model with a focus on human-centered communication. OpenAI notes that it is better at recognizing intonation, emotion, and subtext, and is significantly less hallucinatory

And it’s not only better at recognizing intonation, emotion, and subtext, it’s also significantly less hallucinatory

• Writing emails where tone is important (e.g., dialogs with customers or employees)
• Preparing “gentle” explanations on difficult topics: termination, delays, work conflicts
• Emotional support and discussion of personal problems
• Creative writing: stories, scripts, dialogues

Example: If you want to write a letter to an employee about reassignment of duties and not offend him/her, GPT-4.5 will help you to formulate everything correctly and gently.

o3 – expert in analysis and logic

o3 is the most logical and “thinking” model. It literally thinks before it responds: it builds an internal dialogue, analyzes the essence of the problem, looks for approaches, and tests intermediate hypotheses.

• Detailed data analysis
• Financial and legal modeling
• Strategy building
• Writing reports, forecasts and development scenarios
• Finding non-standard solutions

o3 is able to search the internet, check sources and work with multiple steps of reasoning in a row.

Example: upload an Excel file with sales and o3 will turn it into a report with charts, identify seasonal trends and suggest how to increase conversion.

o4-mini and o4-mini-high – engineers and programmers among the models

The o4-mini models are lightweight but powerful AI models specifically designed for technical tasks.

• o4-mini – basic version
• o4-mini-high – same model, but with higher computational load and better accuracy

• Assist in programming (parsing other people’s code, writing functions, explaining algorithms)
• Processing and analyzing large amounts of data
• Scientific calculations
• Mathematical problems

Example: you’re analyzing the codebase of a Python project and want to identify bugs or improve the architecture – o4-mini-high will do the job faster than other models.

Pro ($200/month) and Enterprise only

o1 pro -heavy artillery for specialized tasks

This is OpenAI’s most resource-intensive model. It features increased accuracy in complex technical areas, but can only be used five times per month.

• Preparing documents for regulation and compliance (e.g. GDPR)
• Analysis of large program code
• Technical documentation for engineering solutions
• Legal or audit expertise

Older models

GPT-4

Officially phased out in April 2025. Was the backbone of ChatGPT Plus from 2023, but gave way to the faster, cheaper, and more functional GPT-4o.

What’s next

GPT-5, the new flagship model from OpenAI, will be released in the summer of 2025. It will combine GPT-series and “o”-series into a single lineup. The GPT-5 is expected to be more powerful, more accurate and truly versatile.

Close: Which model to choose?

The article Guide to all ChatGPT AI models: which one to choose and for what was first published at ITZine.ru.