What is fbclid? the new facebook parameter

Question

For two days, I have noticed that the URL that I publish on Facebook, there is a parameter is added:
?fbclid=uFCrBkUgEvKg...
To be more precise something like: http://example.com?fbclid=uFCrBkUgEvKg...

Does anyone know what this parameter does?
What is it for and what is the use of the developers?

Thanks for your comments.

To me it just looks like facebook is trying to bypass cookie laws... Part from that... seems no one found any documentation on this tracer... — Antony Gibbs, Oct 22 '18 at 16:28
This behavior is so annoying, it's causing all referral traffic to show as unique urls in my analytics reporting since the query param is different per user. — Brian Surowiec, Nov 02 '18 at 15:45
There's some discussion about fbclid in this HN thread (lots of informative links buried in there somewhere): https://news.ycombinator.com/item?id=18275061 — ahiijny, Nov 03 '18 at 03:53
I wrote a Chrome extension that removes it. https://chrome.google.com/webstore/detail/ideekmlpolffjogehcjblcoajcnieeho/publish-accepted?hl=en-US — R OMS, Dec 15 '18 at 02:21
oneliner to remove everything: history.replaceState(null, '',location.origin+location.pathname) — Zibri, May 09 '19 at 14:16
This question is closed (grr) but one thing nobody else mentioned is that you could use it yourself to track unique clicks and cross reference that with stats provided by Facebook. You can use it to see how many unique (paid $$$) clicks you get actually result in a complete page loading on your site. (This would not be something everyone would want to do - but can help in site optimization and page loading). — Simon_Weaver, Oct 02 '19 at 19:24
I have to kind of take my last comment back. It seems it is not ALWAYS sent. I thought I could rely on it being present - but it isn't there - notably it wasn't there within the Facebook App when I clicked on my ad. Presumably because they can track it themselves without the parameter. So basically don't count on it! — Simon_Weaver, Oct 13 '19 at 02:26
There is now a whole website just to explain it: https://fbclid.com — Ooker, Feb 18 '21 at 10:47

score 31 · Answer 1 · edited Mar 18 '19 at 05:13

31

I know that gclid, is short for (Google Click Identifier)
It's a unique tracking parameter that Google uses to transfer information between your Google Ads account and your Google Analytics account.

Facebook must be doing the same thing or something similar with fbclid to improve tracking analytics systems.

edited Mar 18 '19 at 05:13

Bhargav Rao

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answered Oct 17 '18 at 11:40

Marcin Milowski

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while breaking caching worldwide :D at the same time. for many people – Luka Jan 07 '19 at 16:58
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@Luka - you can still use caching. You just need to exclude fbclid, gclid and utm parameters from your cache :) Plenty of solutions support this. – LucasRolff Feb 14 '19 at 05:15
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Some caching plugins don't have such option and what they do is actually for each url create separate cache page which equals to no caching (cuz fbclid is never the same). Nginx implementation to remove it is the best. https://gist.github.com/lynt-smitka/b5ff2cab70443c17a214006a4d5bc48c?fbclid=IwAR1Oxrf4zvchNGSKWjtYdQ_4XXVGAcz-27ucaqGcAzRk2DXbT9SzoU0xb4g – Luka Feb 14 '19 at 20:47
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If the point of this query is to track visitors then should have been stated in docs or in privacy policy. It seems that the fblcid is unique per user. If that is indeed the case there is a huge privacy issue and a GDPR violation. – fat_mike May 29 '19 at 22:23

score 18 · Answer 2 · edited Nov 19 '18 at 17:13

18

This helped me: https://greasyfork.org/en/forum/discussion/44083/fbclid-tracking-parameter-attached-by-facebook

Here is cite from the link:

Put this code in your .htaccess file:

RewriteCond %{QUERY_STRING} "fbclid=" [NC]
RewriteRule (.*) /$1? [R=301,L]

If you work in WordPress:

RewriteEngine On
RewriteBase /
RewriteCond %{QUERY_STRING} "fbclid=" [NC]
RewriteRule (.*) /$1? [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

edited Nov 19 '18 at 17:13

Pat J

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answered Oct 18 '18 at 15:12

no one special

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Who does not work the options above try using this: `RewriteCond %{QUERY_STRING} ^(.*)&?fbclid=[^&]+&?(.*)$ [NC] RewriteRule ^(.*)$ /$1?%1%2 [R=301,L]` – Rafael Dorado Oct 25 '18 at 18:14
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The solution in this answer will override your entire query parameters, e.g. everything after '?' will get thrown away. This may break some functionality of webpages that use query parameters. So, make sure this is what you want. Also, look at answers on stackoverflow / serverfault for how to remove specific query parameter. – Sybille Peters Nov 15 '18 at 14:13
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thanks u save my day – sayalok Mar 12 '19 at 17:47
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Makes me think all web servers should rewrite to something random and forward a new request to FB's servers ;) – youcantryreachingme Aug 29 '19 at 02:46

score 13 · Answer 3 · answered Nov 20 '18 at 09:16

Another approach, how to remove this parameter (so your users can share your URL without removing it manually) is to use JavaScript and history.replaceState.

All credits go to original author - https://www.michalspacek.cz/zmena-url-a-skryvani-fbclid-pomoci-javascriptu

Code from link:

(function() {
        var param = 'fbclid';
        if (location.search.indexOf(param + '=') !== -1) {
                var replace = '';
                try {
                        var url = new URL(location);
                        url.searchParams.delete(param);
                        replace = url.href;
                } catch (ex) {
                        var regExp = new RegExp('[?&]' + param + '=.*$');
                        replace = location.search.replace(regExp, '');
                        replace = location.pathname + replace + location.hash;
                }
                history.replaceState(null, '', replace);
        }
})();

one liner to remove everything: history.replaceState(null, '',location.origin+location.pathname) — Zibri, May 09 '19 at 14:15

score 13 · Answer 4 · answered Nov 29 '18 at 15:51

As I understand it, the parameter is a means of tracking the site visitor so that if your site includes advertising from Facebook, they can customise it to match the recorded browsing habits of the visitor.

The Apache mod_rewrite solution above is problematic because it strips the entire query string. If the URL already had a query string, this will break it. To strip just the fbclid parameter, it's useful to note that Facebook always appends it to a URL, so it's always last. That simplies the mod_rewrite code a little. This is what I do:

# Strip Facebook spyware tokens
RewriteCond %{REQUEST_METHOD} =GET [NC,OR]
RewriteCond %{REQUEST_METHOD} =HEAD [NC]
RewriteCond %{QUERY_STRING} ^(.*)&?fbclid=[^&]+$ [NC]
RewriteRule ^/?(.*)$ /$1?%1 [NE,L,R=301,E=limitcache:1]
Header always set Cache-Control "max-age=604800" env=limitcache

The E=limitcache:1 flag and Header directive is to limit how long the 301 redirect is cached. By default many browsers cache it literally forever. This reduces that to one week (or 604,800 seconds). I may be in a minority in thinking this, but that seems good practice to me. I don't know how long fbclid tokens persist, but if they're long-lasting, it means Facebook will be directing visitors to the same URLs for a long time, and if you ever want to support Facebook's targeted adverts, or if they start using the fbclid for other functionality that you need, you may find these permanently-cached redirects come back to bite. But if you're willing to risk it, you can delete both the Header directive and the E=limitcache:1 flag.

The two tests of %{REQUEST_METHOD} are to prevent Apache from redirecting POST requests (or more esoteric requests like PUT or DELETE, if they're relevant). Most browsers change the request to be a GET requests on a 301 or 302 redirect, which is explicitly allowed by RFC 7231. There is a new 308 redirect code must not have its method rewritten, but unfortunately it's not supported by Internet Explorer on Windows 7 (and probably never will be).

Don't contribute to mass surveillance. Remove that `Header` line if you use this, you're not gonna want to make use of the `fbclid`. Funny that "permanent" redirects can have an expiry date, but that's the organic nature of the web for you. :-) — clacke, Mar 11 '19 at 19:33

What is fbclid? the new facebook parameter

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