A snippet of JavaScript (or, originally, a 1x1 image) placed on a website that sends events to an advertising or analytics platform: page views, add-to-carts, purchases, form submissions. The Meta Pixel, Google tag, TikTok Pixel, and LinkedIn Insight Tag are the common ones. Browser restrictions reduced what pixels can observe, which is why platforms now pair them with a server-side Conversions API.
Used in The Signal
Cite this entry:
Agency Echelon. "Pixel." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/glossary/pixel/