What Is ChatGPT’s o1 Model and How Can You Use It?

OpenAI continues to develop new models for ChatGPT all the time. The o1 model is a little different from previous models, with a focus on step-by-step reasoning over speed of response. This makes o1 much better for certain types of prompts.

What Is ChatGPT’s o1 Model?

ChatGPT’s o1 model is a large language model that was trained in a different way from previous models. It is designed to be able to perform complex reasoning by stopping to think through multiple stages of the problem before finally generating a response. This makes o1 capable of handling much more complex prompts than models such as GPT-4o which start responding immediately without working through any prior steps.

The o1 model was trained using reinforcement learning, which rewards the model for performing actions that help in achieving the goal and penalizes those that don’t. This teaches the model how to choose the best options when working through a problem, with the outcome being a model that can think through problems to reach the correct solutions.

According to OpenAI, the o1 model achieved a score equivalent to the top 500 students in a USA Math Olympiad qualifier and can outperform humans at PhD level on some physics, chemistry, and biology problems. An improved version of the o1 model, named o3, is due to be released by OpenAI at the start of 2025.

How to Access o1 in ChatGPT

You can access the o1 model in the ChatGPT apps on mobile, desktop, and web, as well as via the API. If you’re using the ChatGPT app, you’ll need to have a ChatGPT Plus, Pro, Team, or Enterprise subscription. Unless you have a Pro subscription, you’re limited to 50 o1 messages a week, with Pro users getting “near-unlimited” access for their $200 a month subscription.

There’s also an o1-mini model which is a smaller, less capable version of the model that’s cheaper to use. Most subscribers get 50 messages per day using o1-mini, with Pro users getting unlimited access.

In any ChatGPT app, if you have the appropriate subscription, you can select the o1 model from the list of available models. Click the current model in any chat and select one of the o1 models to start using it.

How Does o1 Differ From GPT-4o?

The big difference between o1 and GPT-4o is noticeable as soon as you start using it. With GPT-4o, the model will start responding almost instantly to your prompt. With o1, the model will think first and can take a significant amount of time before it finally produces a response.

While it’s thinking, you’ll see a brief explanation of what the o1 model is doing as it thinks. You can click the descriptions to see a detailed breakdown of what is happening. Once o1 has finished working through all the steps, it will output its final response, including how long it took to get there.

The beauty of o1 is that it can try an approach, discard it if it isn’t working, and then try a different approach until it finds a method that works. GPT-4o isn’t capable of doing this and will output a response without checking whether it’s suitable or not. It means that for complex problems, o1 is far more likely to produce useful responses.

The Best Use Cases for o1 in ChatGPT

Currently, the use of o1 is much more limited than it is for models such as GPT-4o, so unless you’re a Pro user, you’ll have to use it a little sparingly. For many prompts, GPT-4o is more than enough for your needs, but there are some situations where o1 is far superior.

The o1 model excels at complex prompts that require some level of reasoning to answer. For example, if you have a coding problem, o1 is far more likely to reach a useful solution than GPT-4o. Complex mathematical problems are also something that o1 is much better at solving, and it can help with generating code based on your designs or instructions.

It’s not just mathematical problems, however. The o1 model is capable of solving complex logic puzzles or even tricky word problems such as cryptic crossword clues, thanks to its superior reasoning capabilities. It can cope with complex writing tasks, too, if you really want help with your English assignment.

What You Can’t Do With o1

The o1 model is not without its limitations, however. It is far slower than other models, often taking several seconds to respond, and the wait time can be even longer for more complex prompts.

Some of the more useful features of GPT-4o are also missing from o1. For example, it’s not possible to search the web using the o1 model, and it can’t be used either in Tasks or Projects at present. You can’t create custom instructions for o1, and it won’t save anything to ChatGPT’s memory.

The o1 model is also unable to use Voice, although with the length of time that it takes to respond, using o1 with Voice would be likely to be a painful experience.

Do You Need ChatGPT’s o1 Model?

If you’re a free user, you don’t get access to the o1 model. Is it worthwhile signing up for a subscription to access o1?

The answer really depends on whether you would use it or not. If you need help with solving complex problems regularly, then o1 can definitely help. If you’re mostly using ChatGPT for simple prompts, however, then it’s probably not going to be worth your while paying for a model that you’ll rarely, if ever, use.

It’s also the case when o3 is released, free users will get access to the o3-mini model, according to Sam Altman himself. You might be better off waiting for that to arrive to try out o3-mini before you make any decision to upgrade.

If you want to use ChatGPT for prompts that involve more complex reasoning, then the o1 model is far superior to GPT-4o. However, the model comes with some downsides, not least of which is that it’s not available to free users, and is fairly limited for most paid users, too.

It also lacks some of the useful features of GPT-4o, such as custom instructions and web search. That said, if you need help with complex problems on a regular basis, it can be an invaluable tool.