Full Answer

The core problem with client-side tracking is that every browser now enforces different privacy restrictions, and the restrictions change with each update.

Safari caps JavaScript-set cookies at seven days through Intelligent Tracking Prevention and reduces that to 24 hours for cookies set after ad click navigation. Firefox Enhanced Tracking Protection blocks known trackers from the Disconnect list and strips third-party cookies in Strict mode. Brave blocks virtually all third-party tracking scripts by default. Chrome eliminated third-party cookies in its Privacy Sandbox rollout. Each browser's restrictions affect client-side tracking differently, creating a fragmented landscape where a tracking setup that works in Chrome fails silently in Safari.

Server-side tracking eliminates this fragmentation by moving event collection off the browser entirely. A lightweight data collector captures events through WordPress hooks — these hooks fire on the server regardless of which browser the visitor uses. The collected events are sent from your server to each platform's API. Safari's cookie restrictions, Firefox's tracker blocking, and Brave's script blocking have no effect because the conversion data never passes through the browser.

First-party data matching strengthens the approach. When a customer provides their email at checkout, the server can hash and send that identifier directly to Meta CAPI, Google Ads, and GA4 without relying on browser cookies for attribution. This first-party identifier persists regardless of cookie expiration rules because it is stored in your WooCommerce database, not in the visitor's browser.

The result is one implementation that produces consistent data across all browsers — no conditional logic, no browser detection, no per-browser workarounds.