AI image generation has been all the rage ever since AI tools let users create images using simple text-based prompts. While ChatGPT’s image prompt has been around for quite some time, Google’s Nano Banana Pro — built on Gemini 3 Pro — has taken the image generations scene by storm. And with the latest launch of ChatGPT’s image generation feature, we thought of comparing both to see which one got the memo better.
ChatGPT’s Image Generation vs Nano Banana Pro’s Image Feature: Basic Differences
ChatGPT works on the GPT Image models (GPT Image 1.5) and is now integrated directly into the ChatGPT model, while the Google Nano Banana Pro uses the Gemini 3 Pro Image. The key feature that sets the Nano Banana Pro apart is its speed and creativity. On the other hand, ChatGPT’s AI image generation tool focuses more on fine-grained control.
Also See: Google Unveils Android XR Smart Glasses with Gemini AI
Time Taken to Create Images
Aforementioned, the Nano Banana and its Pro version are very apt at generating images. While the first draft of the image may not be accurate, the silver lining is that you get to see the mistakes in seconds (instead of minutes), thus allowing you to rectify them quickly. During our tests, the Nano Banana generated an image in under 10 seconds.
On the other hand, ChatGPT takes its own sweet time in generating an image. During our tests, a simple prompt took ChatGPT more than 15 seconds to interpret, process, and create. So when it comes to time, Google’s Nano Banana is the clear winner.
I get that Google has the advantage of having access to a large amount of information, which results in getting information into our hands quickly. Whereas ChatGPT generates based on learned patterns of text and image to create the image. That said, compared to the basic model, even on free accounts, image generation has significantly improved, and the amount of time taken is much less.
However, what irked me was the fact that I had to wait longer to see if it got the prompt correctly. And in case it needs rectification, it just adds to the time.
See Also: How to Schedule Tasks and Set Reminders on ChatGPT
Types of Images Supported
Both ChatGPT and Nano Banana Pro’s image generation models can create from a wide array of images. So, from realistic photos to artistic illustrations, diagrams, or even a simple image from your most random thought, these models let you do that easily.
That said, there’s a slight catch when it comes to both models. OpenAI’s ChatGPT’s expertise is in creating artistic and realistic photos and images. It generates more detailed and realistic images that we can often refine and use. During our tests, we found that Google’s Nano Banana Pro is inclined to make more futuristic images.
For the simple prompt like, “Create an image of people sitting at a tea stall, drinking tea, reading newspapers, and chatting“, these are what the AI image generating tools created.
ChatGPT
Nano Banana Pro
Another example: I entered a prompt to create an image of “human brain anatomy in medical charts” on ChatGPT, and it generated accurate medical chart anatomy while adding correct details at the same time. Again, some of the labels may not be technically correct; however, the image is still acceptable for basic educational.
On the contrary, Gemini created a more futuristic view with several labels being inaccurate or misleading.
As for the prompt, here is what I used for both tools: “Give me an image of the human brain anatomy that shows correct markings.” I agree that the prompt could have been more descriptive, but for the purpose of testing, this is what I used.
Another thing I noticed is that Nano Banana, by default, creates a square-sized image. And despite repeated prompts, it doesn’t change the size of images from rectangle to square, whereas ChatGPT does. And this is a major roadblock for creators like us. In this case, I found ChatGPT to be a better option since it allows more precise control over elements like size, lighting, camera angles, composition, and texture.
Final Thoughts
Both ChatGPT and Gemini’s Nano Banana are powerful image generation tools, each with its own strengths and weaknesses. Nano Banana excels in speed and delivering a modern layout. Meanwhile, ChatGPT stands out in realism, detail, and accuracy, especially if you want more aesthetic, technical, or educational visuals.
