Frequently Asked Questions
Is this tool free to use?
Yes, the tool is completely free. No account, registration, or payment is required.
What can I enter into the input field?
You can enter a plain username (e.g. zuck), a numeric Facebook ID (e.g. 4), or any Facebook profile URL including facebook.com/username, facebook.com/profile.php?id=…, or facebook.com/people/Name/ID format. The tool normalises all of these automatically.
Do I need to be logged in to Facebook?
No. Results may vary for accounts with strict privacy settings, as those profiles limit what is publicly accessible.
How accurate are the results?
UIDs are fetched directly from Facebook and are 100 % accurate. Since UIDs are permanent identifiers they will never change for a given account.
Why would I need someone's Facebook UID?
Common use cases include building Facebook Login integrations, targeting specific accounts in the Graph API, configuring ad audiences, or identifying an account reliably when its username has changed.
Is it legal to look up a Facebook UID?
Yes. UIDs are part of Facebook's publicly accessible data. This tool only retrieves information that Facebook itself makes publicly available — no private data is accessed.
What if the tool can't find a UID?
This typically happens when a profile is set to private, the URL is malformed, or the account has been deactivated. Double-check that the input is copied directly from a browser address bar and that the profile is publicly viewable.