When you open a private profile, Instagram's servers do not send the post data to your device. Period. The server checks three things:

What is your in viewing the profile? (e.g., reconnecting with an old friend, business research, curiosity?) Do you share any mutual friends with this user?

Requests for your own Instagram password to "sync" the viewer.

If you want to see a private account's content safely and legally, experts recommend:

But here's what you absolutely need to understand before you click another link or download another "viewer" – these tools don't work, and they're designed specifically to take advantage of your curiosity to steal your information, infect your devices, or worse.

You never see the private photos because they don't exist. You just made the scammer $2.00 in ad revenue and gave them your phone number for spam texts.

If these tools cannot actually access private Instagram servers, what happens when you use them? The business model of these websites relies on deception, user data collection, and advertising revenue. 1. The Visual Illusion

To understand why "private profile viewers" are fake, you need to understand how Instagram actually works from a technical standpoint.