What a Facebook ID actually is

Every account, page and group on Facebook has two names: the vanity URL you see (facebook.com/zuck) and a permanent numeric ID (4). The vanity URL is a label the owner can change at any time. The numeric ID is assigned once, at creation, and never changes — which is exactly why every Facebook developer tool asks for the number and not the name.

Because IDs are handed out in sequence, the number also tells you roughly how old an account is. ID 4 belongs to Mark Zuckerberg; a 15-digit ID starting with 1000 was created many years later. A short ID on an account claiming to be new is a useful signal that something does not add up.

Which URL formats work

Paste the URL exactly as Facebook shows it. The parser handles the following shapes:

Vanity profile and page URLs — facebook.com/zuck
Numeric profile URLs — facebook.com/profile.php?id=100041844794624
Groups, including the mobile domain — m.facebook.com/groups/finduid
Legacy page URLs — facebook.com/pages/Some-Page/1234567890
Individual posts — /posts/…, permalink.php?story_fbid=…, story.php?story_fbid=…
Photos and videos — photo.php?fbid=…, video.php?v=…

A trailing slash is added automatically, so both facebook.com/zuck and facebook.com/zuck/ behave the same. Tracking junk after ?fbclid= is ignored.

Profile ID vs Page ID vs Group ID

The three object types look similar in a URL but behave differently, and mixing them up is the most common reason an API call fails later.

A profile ID identifies a person. Most Graph API endpoints will not return data about a profile unless that person has authorised your app — having the ID does not grant access.

A page ID identifies a business or public figure page. Pages are public objects, so a page ID is what you need for the Page Plugin, Messenger links and most embedding.

A group ID identifies a group. Private groups return an ID but little else; group content requires the group to install your app.

Why a lookup fails, and what to do

A lookup returns "Not Found" for a small number of specific reasons:

The profile is private or restricted in your region. Facebook serves no public data for it, so there is nothing to read.
The account, page or group has been deleted or renamed. An old vanity URL stops resolving the moment it is changed.
The URL is from a logged-in view — anything containing /me/, a session token, or copied from the app's internal share sheet. Open the profile in a normal browser tab and copy the address bar instead.
The link is a shortened or share redirect (fb.me, l.facebook.com). Use the origin link tool first to unwrap it, then paste the real URL here.
Facebook is rate-limiting requests from the server. This is temporary — wait a minute and try again.

What developers use the ID for

The numeric ID is the input for most of the Facebook developer surface: the Graph API (/v21.0/{id}), the Page Plugin and Like Box embeds, Messenger deep links (m.me/{id}), Business Manager asset assignment, and ad audience targeting. Social-media schedulers and CRM integrations ask for it when you connect a page.

It is also the stable key to store in your own database. If you save the vanity URL instead, your records break silently the first time someone renames their page.

Frequently asked questions

Is this free, and do I need an account?

Yes, free, and no account. There is no sign-up, no quota and no limit on lookups. A captcha appears to stop automated abuse.

Does the person know I looked up their ID?

No. The ID is public information attached to a public URL. Nothing is sent to the account owner and no notification is generated.

Can I find the ID of a private profile?

Only if the profile URL itself is publicly reachable. If Facebook hides the profile from logged-out visitors, the tool sees the same empty page you would and returns nothing.

Why does the same URL sometimes return instantly?

Results are cached. The first lookup of a URL is fetched live; after that the stored ID is returned, which is why repeat lookups are immediate. IDs never change, so a cached answer stays correct.

What can I do with the ID?

Anything the platform allows for public data — API calls, embeds, scheduling tools. It does not grant access to private content, and it is not a way to recover a lost account.

Find Facebook ID