To know if someone has blocked you on Snapchat, look for the following signs:

• You cannot find their username or profile in Snapchat search results from your account.
• Previous conversations with them disappear or become inaccessible.
• They no longer appear in your Friends List.
• You cannot see their Snap Score, Bitmoji, or stories.
• Messages or snaps you send them remain stuck on "Pending" indefinitely.
• Using another Snapchat account to search for their username shows their profile, but it doesn’t show up on yours.

These indicators strongly suggest you have been blocked. Note that if their account is deleted or deactivated, some of these signs may also appear, so checking with another account can help confirm if blocking is the cause.