What Is a Website Custom Audience on Meta?

Your website already tells Meta who visited, if the Meta Pixel is installed and active. A website custom audience turns that record into a group you can show ads to, leave out of an ad set, or use as a lookalike source. Meta lists retargeting recent visitors who haven’t converted, finding new customers similar to existing ones, and upselling past buyers as typical uses. Meta may also add people to the audience using on-platform events, not only pixel data.

Which rules can I use?

Each rule looks back a number of days and either includes or excludes people.

Rule	Who it captures	Maximum lookback
All website visitors	Everyone who visits pages with your pixel	180 days
People who visited specific web pages	Visitors to URLs that contain, don’t contain or equal what you enter	180 days
Visitors by time spent	The top percentile of visitors by time on site	180 days
Meta Pixel events	People who fired a standard or custom event, such as AddToCart	180 days; 2 years for purchase events

You can refine event rules by URL or parameter (for example, purchases of at least $50), by frequency of visits, or by device. You can combine up to 5 rule sections, and at least one must include people. Each event can take up to 5 filters, and each event can have up to 10 parameters.

How do I create one?

1. Confirm your Meta Pixel is active on your website.
2. Open Audiences, select Create audience, then Custom audience.
3. Select Website, then Next.
4. Choose whether people must meet any or all of your criteria, then pick your pixel as the source.
5. Choose events or URLs, set audience retention in days, then name the audience and click Create audience.

When you type a custom parameter, enter its name exactly as your pixel, SDK or Conversions API sends it. Meta says these names are case- and space-sensitive, and custom parameters have no dropdown.

Why is my new audience empty or small?

Three reasons Meta documents:

• It doesn’t backfill. A website custom audience starts populating from the moment you create it, so past visitors aren’t added.
• It has to populate. Check the audience’s status in Audiences before using it.
• iOS 14 changes. Your audience may shrink because it may not include events from some iOS 14 users. Using it as a lookalike source doesn’t affect the lookalike’s size.

Meta also notes that the size column may show unavailable or populating even when the audience is ready, when it can’t show the size for privacy reasons.

FAQ

Do I need to update the audience as new people visit?

No. Meta says your website custom audience updates automatically as people who match your rules visit pages with the pixel. People also drop out once they pass your lookback window without returning. You only need to edit it if you want to change the rules or the time period.

What URL should I enter for a specific page rule?

Use the shortest part of the address that still identifies the page. Meta points out that not everyone loads a site with https or www, so matching on a distinctive fragment is safer. The “equals” option needs the full, exact URL from your site, so reserve it for one fixed page.

Does a website custom audience use only pixel data?

Not always. Meta says it may also add to your website custom audience using on-platform events, and its “All website visitors” rule uses both pixel data and on-platform events. The articles cited here don’t list which on-platform events count, so don’t treat the audience as a pure log of pixel hits.