The short answer
When you watch a Story or Highlight while signed in through Instagram, the platform may associate that view with your account and may make viewer information available to the owner. What the owner can see depends on Instagram's current product behavior and how recently the original Story was published.
Why anonymous viewers are different
A public anonymous viewer does not use your personal Instagram session to request the content. That means your own username is not submitted in the normal signed-in viewing flow. This distinction is the main reason people search for an anonymous Instagram Highlights viewer.
Public access is still required
Anonymous does not mean unrestricted. The profile must be public and the Highlight must remain publicly available. A legitimate viewer cannot open private profiles, Close Friends content, deleted Stories or Highlights removed by the account owner.
Do not sign in through an unknown viewer
If a site requests your Instagram password, two-factor code, recovery code or session cookie, it is no longer a no-login viewing flow. Leave the page instead of providing credentials. Installing an unknown extension or APK creates the same unnecessary risk.
Check the state before drawing conclusions
No result can mean several things: the username may be wrong, the account may be private, the Highlight may have been removed, or the service may be temporarily unable to retrieve the public page. A trustworthy viewer explains these possibilities instead of showing fake progress.
A practical privacy checklist
Use an exact public username, keep your Instagram credentials out of third-party tools, avoid claims about private access, and treat public content responsibly. For repeat checks, save the public profile in Telegram rather than repeatedly entering personal account details elsewhere.