Tides have changed with the Gemini 3 update, bringing Nano Banana Pro image generation to a wider range of users. The images are so realistic that Google provides an extension that detects images with hidden watermarks. Here’s how to check if an image is AI-generated.
In recent iterations of Google’s Nano Banana, AI-generated images come with invisible watermarks that indicate the photo was created using a generation engine. The latest update means images are even more realistic, which makes Google’s AI detection tool all the more useful.
According to Google, every image generated by Gemini 3 Pro carries SynthID markers. Gemini’s models can detect them, but it won’t be immediately apparent to those who view the image on their devices.
The marker is detectable using the SynthID extension in the Gemini app. If any portion of an image contains those markers, Gemini will be able to report back with confidence that the image was created using AI.
How to detect an AI-generated image
Using Gemini, users can ask whether an image has been created with Nano Banana or generated with other models in general.
- Open the Gemini app or website.
- Tap Add files +.
- Upload the suspected image.
- Ask a verification question:
- “Was this created or edited with Google AI?”
- “Is this image real?”
- “Is this AI-generated?”
Note: You can also type “@synthid” after attaching an image.


Image detection limitations
Gemini can only give a confident answer regarding images generated using Nano Banana Pro. If asked whether an image is real when presented with a photo generated by another AI model, like ChatGPT, Gemini will not be able to tell with 100% certainty. That’s because other generation tools don’t use the same identifying watermark.
Gemini will still be able to examine the image in shockingly granular detail, pointing out nuances of the image that pose as red flags. It will point out visual inconsistencies like hair blending and symmetry, along with taking into account the aesthetic of the image.
Still, without a SynthID marker, it can’t identify an AI-generated image with absolute certainty.
FTC: We use income earning auto affiliate links. More.


Comments