When you upload your creative, you have the option to add a tracking pixel, which is a small snippet of code that you can attach to your ad. When your ad is served to a viewer, the pixel "fires," sending a signal back to that third party to record that the ad was shown.
It's important to know that a creative tracking pixel is different from a website conversion pixel. A conversion pixel lives on your website and tracks what people do after they see your ad (like making a purchase). A creative tracking pixel, on the other hand, sits on the ad itself and tracks the delivery of the ad to confirm it ran.
What a creative tracking pixel helps you achieve
Adding a tracking pixel to your creative lets you:
Independently verify delivery — confirm your ad was served, using your own measurement source alongside the Ads Manager's reporting.
Count impressions in one place — if you're running ads across multiple platforms, a pixel lets you tally all your impressions in a single third-party tool for an apples-to-apples view.
Do I need a pixel?
A tracking pixel is completely optional. If you don't work with a verification partner, you can leave this field blank when setting up your creative — your campaign delivery and results will still be fully tracked within the platform's own reporting. It's most useful for advertisers and agencies who want to measure delivery independently or consolidate reporting across several platforms.