The algorithm behind ChatGPT is called, well, GPT! Just like all computer programs, there are several versions. We have two versions available to us:
GPT-3.5: a fast algorithm with some limitations in terms of creativity and reasoning skills. This is the algorithm you’re using in the free version of ChatGPT.
GPT-4: a more recent version of the algorithm, which is a little slower but a lot more powerful. It’s only currently available if you pay a $20 monthly subscription for ChatGPT Plus (which also gives you priority access to ChatGPT at busy times).
Subscribe to ChatGPT Plus
If you want to use GPT-4, you need to pay for it, and that means a $20 monthly subscription for ChatGPT Plus. However, you can unsubscribe at any time.
So, how do we set it up? Start by clicking on Upgrade Plan in the bottom left corner of the ChatGPT display:
You’ll then see a short description of ChatGPT Plus, showing the differences compared to the free version and the price:
If you click on the Upgrade to Plus button, you’ll need to complete a form and provide your billing and payment card details.
Once you’ve done this, you can access ChatGPT Plus straight away.
Choose Your Algorithm
Now that you subscribe to ChatGPT Plus, each time you start a new conversation, you can use a button to switch between the different algorithms:
You have two options:
GPT-3.5: the default algorithm used by everyone on the free version of ChatGPT
GPT-4: the latest, most powerful algorithm. As a ChatGPT Plus subscriber, you can use this one! And that’s the one I would recommend.
But you can already enjoy higher quality responses with GPT-4. As a test, try asking it “Why is the sky blue?” and you’ll see that GPT-4 gives a much more detailed and logical response.
Question | GPT-3.5’s response | GPT-4’s response |
Why is the sky blue? | The sky is blue due to the interaction between sunlight and the Earth’s atmosphere. Blue light, with its shorter wavelength, is scattered more efficiently than red light. | The blue color of the sky is primarily due to a phenomenon called Rayleigh scattering. This phenomenon occurs because of the interaction between sunlight and the molecules and small particles in the Earth’s atmosphere. This scattering is more effective for shorter wavelengths, like blue, causing the sky to appear predominantly blue to our eyes. During sunrise and sunset, the sky takes on a red hue because the sunlight has to pass through more of the Earth’s atmosphere, which absorbs and scatters more of the blue light. |
How does nuclear fusion work? | Nuclear fusion is the process by which two light atomic nuclei combine to form a heavier nucleus, releasing energy in the process. Fusion requires extremely high temperatures and pressures, like those found within stars. | Nuclear fusion is the process by which two light atomic nuclei, typically isotopes of hydrogen, overcome the repulsive electrostatic force (Coulomb barrier) to get close enough for the strong nuclear force to take over. This creates a heavier nucleus, releasing a significant amount of energy in the form of radiation and particles. This is the same process that powers the sun and other stars, and scientists are currently working on controlling fusion to provide a nearly limitless and clean source of energy on Earth. |
What are the causes and consequences of climate change? | Climate change is primarily caused by greenhouse gas emissions and its consequences include a rise in sea levels, higher temperatures and extreme weather conditions. | The primary cause of climate change is the emission of greenhouse gases by human activity, including carbon dioxide and methane, which results from burning fossil fuels, deforestation and agriculture. The consequences include rising sea levels, increased global temperatures, melting ice, ocean acidification, loss of biodiversity, more frequent and intense extreme weather events and adverse effects on human health, the economy and food security. |
The difference isn’t always so marked, but if you want to and are able to, I’d recommend using GPT-4 as much as possible with your ChatGPT Plus subscription.
Let’s Recap
GPT-3.5 is a fast algorithm with limited creativity and reasoning skills, which is available to all ChatGPT users using the free version.
GPT-4 is a more recent and powerful algorithm, albeit a little slower, and is only available when you subscribe to ChatGPT Plus at a cost of $20 per month.
To subscribe to ChatGPT Plus, you just need to click on “Upgrade Plan” and complete the payment form to start using the advanced features, such as priority access and new features.
A drop-down list at the top of the screen lets you select the algorithm you want to use for each new conversation, i.e., GPT-3.5 or GPT-4.
Now that you are aware of the Premium version of ChatGPT, let's use it to search the internet.
