What is Pixel in advertising?

Pixel (Tracking pixel): what it means in advertising

Definition

A pixel is a snippet of JavaScript on your site that reports visitor actions back to an ad platform: page views, add to carts, purchases and any custom events you define. It does two jobs at once. It measures what your ads produced, and it feeds the conversion signal the platform's automated bidding learns from.

What to know

Browser-only pixels lose events to ad blockers and tracking prevention, and the loss is not evenly spread, so it distorts which audiences look valuable rather than simply shrinking the totals. Pairing the pixel with a server-side feed is the standard fix.

Firing a purchase event on a page the customer can refresh, or on a step that is not the actual purchase, corrupts the signal quietly. Confirm the event fires once, on the right page, with the correct value and currency, before trusting anything built on it.

Related terms

Conversions APIThe Conversions API (CAPI) is Meta's server-side channel for sending conversion events directly from your serv...Server-side trackingServer-side tracking sends conversion data to ad platforms from your own server rather than from the visitor's...Custom audienceA custom audience is an audience built from your own data rather than from platform interest categories: a cus...Conversion rateConversion rate (CVR) is conversions divided by clicks or sessions, expressed as a percentage. If 1,600 clicks...

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