Instagram doesn't support photo deletion on computers, but you can achieve it with the trick below.

Note: Instagram currently maximizes support for mobile platforms, so we'll need to simulate a mobile platform on the browser. Browsers that can do this include Chrome, Coc Coc, Microsoft Edge.
Step 1: Go to Instagram on the Web and log in as usual. Then, navigate to the Profile section to view the uploaded photos.

Step 2: Next, press F12 or Ctrl + Shift + I on your keyboard to open the page source inspection window.
When the inspection window appears, select the Mobile (phone) icon to activate the mobile interface.

Step 3: With the phone mode selected, a completely new custom toolbar will appear above the interface. Here, click on Responsive and choose any mode you prefer (usually select iPhone X or iPad/iPad Pro).

Step 4: Finally, press F5 or Reload button to refresh the Instagram page.

Step 5: Now, simply select the image and click on the three-dot icon in the top right corner to reveal the option to delete the photo.

Only the mobile interface on the Web platform allows you to delete photos on Instagram. If you use the default computer platform, you won't be able to delete. Here's an example when the software trick hasn't switched to the mobile interface.

In this article, the software trick has guided you on how to quickly and effectively delete photos on Instagram using a computer. Wishing you a joyful day!
