Often, the same profile picture appears in other contexts. Go to the user’s “Photos” tab and look at albums where they are tagged by friends. Those images are not locked. You might find a higher-resolution version there.
: Some guides suggest using verified services like those found on Fiverr for ethical viewing of public-level information in clearer formats. Manual Workarounds and Alternatives facebook locked profile picture viewer online top
Some slightly more technical tools will take the low-resolution thumbnail (which is public) and run it through a reverse image search engine to find larger versions elsewhere on the web. This works only if the user has posted the same high-resolution image publicly on another site (e.g., Twitter, LinkedIn, or a blog). This is not hacking Facebook; it is just basic OSINT (open-source intelligence). And it fails 99% of the time. Often, the same profile picture appears in other contexts