Check if you can still find their profile in search
See if their profile shows “User not found” when you open it
Try viewing their posts; if you can’t see any posts or only see limited content, it may indicate a block
Check whether you can still see their follower/following counts and posts
Look for their name in your direct message thread; if the chat disappears, it may indicate a block
Send a message and see if it stays “pending” without delivering
Try sending a message from a different account you control; if it can message but your main account can’t, it may indicate a block
Check if you can still tag them in comments or posts
See if your mentions/comments appear publicly on their account
Look for changes in your ability to view their stories after you previously could
Confirm they didn’t simply make their account private or deactivate it, which can look similar to blocking