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Home Innovation Artificial Intelligence

How to use ChatGPT: Everything to know about using GPT-4o and GPT-4o mini

Want to use the most popular AI chatbot available? We'll walk you through how to get started with ChatGPT and how to get the most out of it.

Written by Maria Diaz, Staff Writer Aug. 21, 2024 at 1:08 a.m. PT

Reviewed by Min Shin and Alyson Windsor

OpenAI ChatGPT GPT-4o — Maria Diaz/ZDNET

OpenAI unleashed an artificial intelligence (AI) revolution when the company launched ChatGPT for public use in late 2022. Since then, ChatGPT, a chatbot powered by OpenAI's large language models (LLMs), has dominated headlines and preoccupied the minds of executives running Twitter, Google, Amazon, Microsoft, and Meta, inspiring them to create their own generative AI projects.

Also: ChatGPT vs. Microsoft Copilot vs. Gemini: Which is the best AI chatbot?

Though OpenAI offers a paid ChatGPT Plus subscription for $20 a month, free ChatGPT users can do a lot without the monthly fee. This includes accessing the GPT Store to use custom GPT bots, generating images, enjoying a sense of continuity in their conversations with Memory, uploading photos and documents to discuss them with ChatGPT, having the bot browse the web to give more current context, using advanced data analysis, and access to GPT-4o mini and GPT-4o, OpenAI's newest and most advanced LLM.

How to use ChatGPT

ChatGPT has many capabilities that you can use for free, so we'll cover how you can access the AI chatbot to try these features yourself.

1. Go to ChatGPT.com

Start by going to ChatGPT.com. You no longer need to create an account on OpenAI's website to log in and access ChatGPT, but you must create a free account to access GPT-4o, view past conversations, generate images, and upload files. You also need to log in to use ChatGPT Plus.

Also: ChatGPT vs. ChatGPT Plus: Is a paid subscription still worth it?

To create an account, click "Sign up" on the bottom left of the chat screen and follow the prompts to enter your information. OpenAI requires a valid phone number for verification to create an account on its website.

Go to ChatGPT.com — Screenshot by Maria Diaz/ZDNET

2. Learn how to use ChatGPT

Once you open ChatGPT, learn how to navigate the user interface. Here's a breakdown of what you will see, with the image below as an example:

Close sidebar and Chat buttons: On the left side of your screen, there's a button that closes the sidebar and a 'New chat' button that you can click on to start a fresh conversation anytime. ChatGPT remembers what you discussed previously in a conversation and will respond with context. Starting a new chat creates a new discussion without context, though the bot may remember some details if you're logged in.
Chat history: The left sidebar keeps your past conversations accessible in case you need to return to one (you can edit the title of each chat). You can also share your chat history with others, turn off chat history, delete individual chats, or delete your entire chat history. This is also where you can find the GPTs you've used in the past.
Account (if logged in): Clicking on your name on the bottom left of your screen gives you access to your account information, including settings, the option to log out, get help, and customize ChatGPT. If you don't have ChatGPT Plus, you may see an 'Upgrade plan' button here to sign up for it.
ChatGPT dropdown menu: You can choose which model to use near the top of the screen, above your conversation. The options in the menu include ChatGPT Plus, ChatGPT, and Temporary Chat. ChatGPT Plus requires a subscription; ChatGPT uses GPT-4o until you reach your rate limit, then automatically switches to GPT-4o mini; and Temporary chat starts a chat that won't appear in your history, won't be used in model training, and will have the Memory off.
Your prompts: The questions or prompts you send the AI chatbot appear in the middle of the chat window, with your account photo or initials to the left.
ChatGPT's responses: Whenever ChatGPT responds to your queries, the logo will appear on the left. Below each response, you'll see Read Aloud, Copy, Regenerate, Thumbs Down, and Change model buttons. You can copy the text to your clipboard to paste it elsewhere and provide feedback on whether the response was accurate. OpenAI uses this human feedback to fine-tune the AI tool through reinforcement learning.
Text area: This is where you enter your prompts and questions.
ChatGPT disclaimer: OpenAI includes some fine print below the text input area. The disclaimer reads: "ChatGPT can make mistakes. Check important info." OpenAI includes this disclaimer because chatbots like ChatGPT can hallucinate and give nonsensical answers (always make sure to fact-check their responses). This section previously showed the version of the ChatGPT model currently in use, but OpenAI removed this option.

Also: How to use ChatGPT to analyze PDFs (and more) for free

New ChatGPT UI launched by OpenAI — As you can see here, I've logged in to ChatGPT. This is the new UI launched by OpenAI.
Screenshot by Maria Diaz/ZDNET

3. Start writing your prompts and questions

Now that you know how to access ChatGPT, you can ask the chatbot any burning questions and see what answers you get -- the possibilities are endless. The ChatGPT tool can be useful in your personal life and many work projects, from software development to writing to translations.

Also: 5 ways ChatGPT can help you write an essay

Type a ChatGPT prompt in the text bar at the bottom of the page, and click the submit button to pose your questions. The chatbot will then generate text to answer your query.

ChatGPT doesn't work like a search engine. Instead, the chatbot responds with information based on the training data in GPT-4 or GPT-4o. The free version of ChatGPT uses GPT-4o mini and GPT-4o (when available), which is OpenAI's smartest and fastest model. Like GPT-4o, GPT-4 -- accessible through a paid ChatGPT Plus subscription -- can access the internet and respond with more up-to-date information.

Log in to ChatGPT — Screenshot by Maria Diaz/ZDNET

ZDNET's ChatGPT guides

ChatGPT users have come up with creative ideas for using the chatbot, from asking questions in search of funny answers to correcting a bug in code. Across all these areas, one thing is abundantly clear: this AI tool is remarkable not due to any particular innovations but rather because it's accessible and easy to use.

Here are some of ZDNET's guides on different ways to use ChatGPT.

How to use ChatGPT for coding

How to use ChatGPT for work

How to use ChatGPT for school

Useful ChatGPT tips

FAQs

How can I use GPT-4o?

GPT-4o is currently available for all ChatGPT users, free and paid. Once you begin using the ChatGPT free tier, you'll start interacting with GPT-4o without selecting it as your preferred model. Once you hit your rate limit of about 15 prompts per three hours, the model will automatically switch to GPT-4o mini.

OpenAI deprecated older GPT models, leaving only GPT-4, GPT-4 Turbo, GPT-4o, and GPT-4o mini.

What's the difference between GPT-4o and GPT-4o mini?

GPT-4o mini is an accessible version of GPT-4o, OpenAI's largest 'omni' model. GPT-4o was launched as the largest multimodal model to date, and it can process visual, audio, and text data without resorting to other AI models, like Whisper, as GPT-4 does. GPT-4o mini is a more cost-efficient model than GPT-4o, though still more capable than GPT-3.5, which previously powered the free ChatGPT tier, and GPT-3.5 Turbo.

Also: What does a long context window mean for an AI model, like Gemini?

Aside from giving free ChatGPT users access to a larger, superior model by defaulting to GPT-4o mini rather than GPT-3.5, OpenAI is making GPT-4o mini a more affordable model in the API for developers. The model is 60% cheaper than GPT-3.5 Turbo, features a 128K token context window, with an output of up to 16K tokens per request, and is trained with information up to October 2023.

What's the difference between free and paid ChatGPT?

Some big differences exist between using the free ChatGPT tier and a Plus subscription. Paid users will have up to five times the limit of free users and can generate more images with DALL-E 3. Subscribers can use GPT-4 when their GPT-4o limit runs out, while free users can use only GPT-4o mini when their quota runs out. ChatGPT Plus users can create GPT bots, while free tier users cannot.

In addition, ChatGPT Plus subscribers have priority access to new features from OpenAI, including the Advanced Voice Mode, which is gradually rolling out now.

What are some good prompts for ChatGPT?

ChatGPT's responses to prompts are good enough that the technology can be an essential tool for content generation, from writing essays to summarizing a book.

The better the prompt, the better the response you'll get. Here are examples of prompts you could start with:

How does a computer store and process information?
Analyze this code and tell me how to fix it: [Paste the code].
Write a poem about migraines in Walt Whitman's style.
What is the difference between a virus and a bacterium?
Write a sick note for my child who has to miss school.
Write a song/poem about [insert topic here] (try adding multiple details).
Give it a list of ingredients from your pantry and ask it to write a recipe with them.
Ask it to summarize ideas or concepts.
Request a packing list for a three-day trip to the beach.

Your imagination is the limit. Have fun with different ChatGPT prompts. For example, ZDNET's David Gewirtz asked the AI chatbot to write a WordPress plugin and used it to help him fix code faster. He also requested ChatGPT to write a Star Trek script and start a business using the technology and other AI tools.

Also: This simple AI tool may be the most useful new Pixel feature (it's in iOS 18, too)

Others have used the tool to write malware. ChatGPT is an AI assistant programmed to reject inappropriate requests and doesn't generate unsafe content, so it may push back if you give it certain potentially unethical requests.

Can I use ChatGPT without a login?

OpenAI allows users to access the free version of ChatGPT, powered by GPT-4o mini and GPT-4o, without logging in, though you must create an account to access your chat history. To access GPT-4, you need an account and a ChatGPT Plus subscription.

Also: My 3 favorite AI chatbot apps for iOS - and what you can do with them

If you'd rather access GPT-4o with a higher rate limit and without logging in to a website, you can use Microsoft Copilot, formerly Bing Chat, which uses OpenAI's GPT-4o. You can log in with a Microsoft account for extended conversations. GPT-4o is a faster and smarter model than GPT-4.

What is ChatGPT Plus?

ChatGPT Plus is OpenAI's paid subscription to ChatGPT that offers access to GPT-4o mini, GPT-4, and GPT-4o. A paid subscription gives you priority access to new features, has a higher usage limit than a free account, and lets you use the AI chatbot during peak times.

Also: If these chatbots could talk: The most popular ways people are using AI tools

Is ChatGPT accurate?

ChatGPT and other AI assistants are prone to misinformation because they're trained on massive amounts of data humans create. These tools can be biased if their data is flawed and can give inaccurate responses, especially regarding world events.

Challenge any incorrect premises and always fact-check information from ChatGPT and other chatbots.

Can I use ChatGPT on my phone?

OpenAI offers mobile apps for iOS and Android. These apps provide a rich ChatGPT experience, letting you talk with ChatGPT through voice conversations powered by OpenAI's Whisper without requiring a ChatGPT Plus subscription.

Also: These are my 4 favorite AI chatbot apps for Android

If you don't want to download an app, use the AI-based tool in your mobile browser. The steps to use OpenAI's ChatGPT from your mobile browser are the same as on a PC. Go to ChatGPT.com and start typing. The AI chatbot should work similarly to when you access it from your computer.