Some "profile viewers" use Facebook’s Graph API or search archived data. However, these can only show images the user has already made public on other platforms or old cached versions — not current private profile pictures.
What you can sometimes see legally:
Attempts to bypass Facebook's profile picture privacy settings using online tools and methods are often unsuccessful due to the following reasons: facebook private profile picture viewer online 2021
Several third-party tools and websites claim to allow you to view private profile pictures online. However, be cautious when using these tools, as some may be scams or malware. Here are a few options: Some "profile viewers" use Facebook’s Graph API or