Facebook IDs and usernames are two different things

A Facebook ID is a long string of numbers that Facebook assigns to every account — for example, 123456789012345. Your username is the custom text you choose, like @johnsmith or @sarah.design. They serve different purposes. Your username is what people type into the search bar or see in your profile URL. Your ID is what Facebook's system uses behind the scenes, and it stays the same even if you change your username.

If you have someone's username, you can find their ID using a few straightforward methods. None of these require special tools or access — they all use information Facebook makes publicly available.

Key Takeaways

  • A Facebook ID is a number; a username is text you choose — they are separate identifiers for the same account.
  • You can find someone's ID by viewing their profile source code, using their profile URL, or using a free online converter tool.
  • The source code method works in any browser: right-click the profile, select "View Page Source," and search for "id" to find the number.
  • If someone's profile is private, you may not be able to see their ID without being friends with them first.

Finding the ID through the profile URL

The simplest method is to look at the web address of someone's profile. If their username is @johnsmith, go to facebook.com/johnsmith and look at the URL in your browser's address bar. If the profile uses a custom username, the URL will show the username, not the ID number.

However, if you click on their profile picture or certain links, Facebook sometimes redirects to a URL that shows the ID instead. The URL would look like facebook.com/profile.php?id=123456789012345. If you see this format, the long number between "id=" and the end of the URL is their Facebook ID.

Using the page source method

This method works on any computer or phone browser. Open the person's Facebook profile, then right-click anywhere on the page and select "View Page Source" (or "Inspect" on some browsers). A window will open showing the code behind the page.

Press Ctrl+F (or Cmd+F on Mac) to open the search box within that code window. Type "id" and the browser will highlight matches. Look for a line that contains a very long number next to "id": — that number is usually their Facebook ID. It will be much longer than a regular phone number, typically 13 to 16 digits.

This method works even on profiles with custom usernames, because the ID is stored in the page code regardless of what username the person chose.

Using an online ID converter

Several free websites convert Facebook usernames to IDs. Search for "Facebook ID converter" or "Facebook username to ID" and you will find sites like findmyfbid.com or similar tools. Paste the username into the search box (without the @ symbol) and the tool will return the ID number.

These tools pull information from Facebook's public data, so they work only for profiles that are not completely private. If someone has locked down their profile so that only friends can see it, the converter may not return a result.

Why you might need someone's Facebook ID

Facebook IDs are useful for developers building apps or integrations that connect to Facebook. They are also used in some third-party tools that analyze or manage Facebook data. If you are trying to contact someone or find their profile, the username is usually all you need — the ID is more relevant for technical work behind the scenes.

Some people look up IDs to verify they have found the correct person, since IDs never change even if someone updates their username multiple times. This can be helpful if you are searching for someone with a common name.

What to do if the profile is private

If someone's profile is set to private and you are not friends with them, you may not be able to see enough of their profile to extract the ID. The page source method sometimes still works because some ID information is embedded in the page even for private profiles, but it is not may provide.

If you need to find the ID of someone whose profile is private, the most straightforward approach is to send them a friend request. Once they accept, you will have full access to their profile and can use any of the methods above.

Frequently Asked Questions

Does finding someone's Facebook ID let me see their private information?

No. The ID is just a number that identifies the account. Privacy settings still explore — if someone's profile is private, you cannot see their posts or photos just because you know their ID. The ID itself is not a password or key to their account.

Can I change my Facebook ID?

No. Facebook assigns IDs automatically and they cannot be changed. You can change your username as many times as you want, but the ID stays the same for the life of the account. This is by design, so apps and integrations do not break when someone updates their username.

Is it against Facebook's rules to look up someone's ID?

No. Facebook IDs are public information for accounts that are not completely private. Looking up an ID using public methods is not a violation of Facebook's terms. However, using an ID to bypass someone's privacy settings or to harass them would be against the rules.

What if the converter tool says the username does not exist?

The username may be spelled differently than you think, or the account may have been deleted. Try searching for the person by name in Facebook's search bar to make sure you have the correct username. If the account no longer exists, there is no ID to find.

Can I use someone's Facebook ID to find them on other websites?

Sometimes. Some third-party sites and databases cross-reference Facebook IDs with other social media accounts or public records. However, this is not reliable — many people use different usernames on different platforms, and privacy settings limit what information is available to search.