Best practices for Meta pixel traffic permissions

You can control if domains are allowed to send events through your Meta pixel using the Traffic permissions feature in Meta Events Manager.

Traffic "allow lists" enable you to choose which domains you want to receive pixel events from while excluding all other events. Traffic "block lists" enable you to choose which domains you want to block pixel events from while including all other events. Learn more about pixel traffic permissions and reasons why you might see pixel events coming from unfamiliar website domains.

Consider these best practices for traffic allow lists and block lists:

• If you use third-party advertising technology or a partner integration that would cause redirects, allow both your business domain and the third-party domain. Some third-party advertising technologies and partner integrations will redirect website visitors to their own domain before visitors land on your domain. We recommend allowing both domains to help ensure that you still receive events sent through your pixel and don't inadvertently block them.
• If you set up your pixel in an inline frame (iframe) and manually set the referring URL to a domain that's different from your business domain, allow them both. This helps ensure that you still receive events sent through your pixel and don't inadvertently block them.
• Set up an allow list if you want to automatically block events from domains you don't recognise. We recommend allow lists because domains that aren't on your allow list are automatically blocked. For this reason, allow lists provide more control over your pixel traffic than block lists. Bear in mind that creating an allow list will immediately stop all events from other domains from being included in your ad performance. You can add or remove domains from a list at any time, but you can't recover events that were lost while a domain was blocked.
• If you already have a block list, you can switch to an allow list at any time. If you switch from a block list to an allow list, the domains on your block list will be removed from the block list and only your allow list will be in effect. This will immediately stop all events from other domains from being included in your ads performance.
• Set up a block list if you want to automatically receive events from your pixel when it's set up on a new domain. If you use a block list, you don't need to edit your Traffic settings to start receiving events from your pixel when it's set up on a new domain. If you use an allow list, you do need to add the new domain to your allow list before you will see events from that domain in Events Manager.
• Add the top-level domain to your list to easily add all subdomains. If you add a top-level domain to a list, all subdomains are also included. For example, adding "domain.com" also adds "m.domain.com". If you don't want all subdomains to be added to your list, add each subdomain separately.