The Meta Pixel is a snippet of tracking code on your website that records what visitors do, so you can build retargeting audiences, measure conversions, and optimize Meta ad delivery. It is the behavioral backbone of Meta advertising, and it is increasingly paired with the Conversions API for server-side tracking.
What it does
The pixel fires when a visitor takes an action, a page view, a lead form, a purchase, and reports it back to Meta. Those events let you build retargeting audiences of people who visited but didn't convert, measure which ads drove conversions, and give Meta's algorithm the signal it needs to optimize delivery.
Why it beats interest targeting for B2B
Pixel audiences are built on what people actually did on your site, not what they self-declared in a profile, so they're accurate where Meta's interest-based B2B targeting leaks. Since browser privacy changes cut client-side signal, most accounts now pair the pixel with the Conversions API (server-side events) to recover measurement. We cover where Meta fits in Meta's B2B targeting is built on self-declarations.