What is Meta Pixel?
The Meta Pixel is a snippet of JavaScript code that tracks visitor activity on a website and reports it to Meta. It loads a small library of functions that the site calls whenever a visitor takes an action, called an event, that the advertiser wants to track as a conversion. Meta uses those events to measure ads in Ads Manager, build custom audiences, run Advantage+ catalogue ads and analyse conversion funnels.
Because the pixel runs in the visitor's browser, an ad blocker can stop it firing. Meta recommends running it alongside the Conversions API, with matching event IDs so duplicates are removed.
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Sources
- 1.The Meta Pixel is a snippet of JavaScript code that tracks visitor activity, used for measurement, custom audiences, catalogue ads and funnel analysis. Meta for Developers, Meta Pixel. Checked 14 October 2026.
- 2.The Meta Pixel may not fire when someone uses an ad blocker. Meta Business Help Centre, About conversion count differences between Meta Ads Reporting and third-party reporting tools. Checked 14 October 2026.
- 3.Meta recommends running the Conversions API alongside the pixel with deduplication. Meta for Developers, Handling Duplicate Pixel and Conversions API Events. Checked 14 October 2026.