Sales Loves MarketingA fired pixel is a tracking pixel that has loaded and reported an event. When a visitor reaches a "thank you" page or opens an email, a tiny piece of code asks a tracking server for an image or script. That request is the "fire", and it tells the platform the event happened. In affiliate marketing, a fired conversion pixel is what credits the affiliate with a sale or lead.
How does a tracking pixel work?
A tracking pixel, also called a web beacon, is usually a 1x1 transparent image or a short script placed in a page's HTML or in an email.
- The page or email loads and the browser or email app requests the pixel from the tracking server.
- The request carries details such as the IP address, the time, the browser or email app, and any cookies the server set earlier.
- The tracking URL often includes an ID for the campaign, click or recipient, so the platform knows whom to credit.
- The server logs the request. The pixel has fired.
Google Ads conversion tracking works the same way. You add the Google tag to your site, a cookie is set when someone clicks your ad, and when they complete an action the tag recognises the cookie and records a conversion.
Where are pixels used?
- Affiliate and partner marketing. A conversion pixel on the order confirmation page tells the affiliate network which partner drove the sale, which triggers a pay-per-sale or cost-per-action commission.
- Advertising. Pixels such as the Facebook (Meta) pixel or Google tag record conversions and build retargeting audiences.
- Email marketing. An invisible image in each email records opens.
- Analytics. Page views and events on a website.
Why do pixels fail or mislead?
- Blockers. Browser extensions such as uBlock Origin, Privacy Badger and Ghostery filter tracking requests.
- Consent. In the EU, the European Data Protection Board's guidelines on Article 5(3) of the ePrivacy Directive, finalised in October 2024, cover pixel and URL tracking as well as cookies. If your consent banner blocks tracking until the visitor agrees, pixels won't fire for people who decline.
- Email privacy features. Apple's Protect Mail Activity downloads remote content in the background, even if the email is never opened, and hides the reader's IP address. Open rates from Apple Mail users are therefore unreliable.
- Setup errors. A missing tag, a redirect before the page loads, or a duplicate tag that fires twice.
Pixel vs postback
A pixel depends on the visitor's browser. A postback URL is a server-to-server message: the advertiser's system tells the tracking platform about the conversion directly. Because the browser is not involved, blockers and cookie limits affect postbacks less. Ad platforms can also take conversions uploaded from your own systems, such as Google Ads offline conversion imports.
Related terms
Frequently asked questions
How do I know if a pixel fired?
Most ad and analytics platforms show a status or recent event list for each tag. You can also open your browser's developer tools, go to the network tab, complete the action and look for the request to the tracking server. For affiliate offers, the network's reporting shows whether a conversion was recorded.
Why didn't my pixel fire?
Common causes are a tag missing from the confirmation page, a page that redirects before the tag loads, a consent banner that blocks tracking until the visitor agrees, or an ad or tracker blocker in the visitor's browser. Test the full journey yourself after every site change.
What is the difference between a pixel and a postback?
A pixel fires from the visitor's browser or email app. A postback, or server-to-server call, is sent by the advertiser's server to the tracking platform. Postbacks don't depend on the browser, so blockers and cookie limits affect them less.