Are you ready to put your observation skills to the test with a fun and brain-teasing challenge? Take a look at these two cartoon-style images that, at first glance, appear almost completely identical. The picture shows a cheerful woman taking a selfie in front of Big Ben, holding a coffee cup, and surrounded by city life. But don’t be fooled—hidden in these illustrations are 15 subtle differences that have left thousands of people puzzled.

One viewer even claimed they attempted the challenge over 465 times and still couldn’t find them all! If you’re someone who loves solving visual puzzles, now’s the time to step up and see how many differences you can spot without looking at the answers. Before you jump in, take a moment to really study the two images. These puzzles aren’t about speed—they’re about focus, attention to detail, and patience. Ask yourself what stands out. Look closely to see if something is missing, added, flipped, or colored differently.

Are objects shaped the same way? Do any items appear smaller or larger? Use your finger or a pen to track changes as you spot them, because your brain is wired to “autofill” familiar visuals, making it easy to overlook what’s right in front of you. So why do most people struggle with these kinds of puzzles? First, it’s human nature to zero in on the main subject—in this case, the woman taking the selfie. You may spend all your energy studying her facial expression, outfit, and coffee cup while completely missing subtle changes in the background or corners of the image. Second, we tend to expect major differences when most of them are small—like a stripe on a cup or a missing window. Third, because our brains are so good at recognizing familiar patterns, we often skip over small inconsistencies that don’t jump out at us. And finally, people often rush through the image without a clear strategy, causing them to miss obvious differences. That’s why a careful, methodical approach is key to finding all 15 changes.

Let’s break down each one: In the top left, a small cloud has vanished in the second image. The airplane in the sky is flying in the opposite direction. Big Ben’s clock has a slightly different design. The woman’s hair color has changed from purple in one image to green in the other. Her left earring is missing. The coffee cup she’s holding has an extra stripe. The number of buttons on her shirt changes—two in one, three in the other. A window on the building behind her disappears. The red car on the street loses its side mirror.

The orange traffic cone beside the dog is missing. The dog’s collar disappears. A dog bone suddenly appears beside the dog. A piece of trash that was on the sidewalk is gone. A hole or patch appears on her pants. Finally, a small orange cat is now sitting beside her leg. Some of these are easy to see once you know what to look for, while others—like the reversed plane or missing window—are easier to miss. Don’t feel bad if you didn’t catch them all on your first try. If you’d like to improve your skills for future puzzles, here are a few tips: Start looking from the corners and work your way inward. People naturally focus on the center of an image, so sneaky changes around the edges often go unnoticed. Try scanning the image row by row, or diagonally, to make sure you don’t miss any part. If you’re using a phone or tablet, zoom in for a better view—some differences are incredibly small. And, of course, practice makes perfect. The more of these you do, the better your brain gets at spotting changes quickly.

So how did you do? Were you able to spot all 15 differences before checking the list? Maybe you got 12? Or just 8? No matter your score, go ahead and comment with how many you found and challenge a friend to beat you. These games can be surprisingly competitive, and they’re a great way to sharpen your attention to detail. Spot-the-difference puzzles are more than just a fun way to pass the time—they’re also fantastic for strengthening your memory, focus, and mental agility. With regular practice, you’ll find yourself picking up on little details in everyday life, whether it’s a typo in an email or a misplaced item in your kitchen. If this puzzle kept you entertained, there are plenty more out there waiting to be solved. Keep challenging yourself, one image at a time, and enjoy the mental workout. Now, without looking, can you remember all 15 differences from memory? Go ahead—give it one more try. Happy puzzling!