Click identifier may refer to several online user tracking mechanisms: DoubleClick Click Identifier (dclid), used by DoubleClick, now Google Facebook Click Identifier (fbclid) used by Facebook in social media analytics Google Click Identifier (gclid, gclsrc, wbraid and gbraid), used by Google Ads Microsoft Click Identifier (msclkid), used by Bing Ads See also Query string UTM parameters Web analytics Social media analytics