Why use both client-side and server-side tracking simultaneously?

Tracking user actions on your website is essential to understanding what’s working in your marketing and where conversions are coming from. Client-side tracking (like a browser pixel) and server-side tracking (like Conversion APIs) each offer benefits, but using them together gives you the most accurate picture. Here’s why combining both is smart.

Client-side tracking allows cross-site tracking in browsers that still support third-party cookies (mainly Chrome, which remains the most widely used browser.) This means you can collect more detailed user data across different websites, which helps advertising platforms better understand user behavior and optimize ad performance.

Client-side tracking relies on users’ browsers to send data. It works well most of the time, but it’s vulnerable to ad blockers, browser restrictions, and iOS limitations. That means lost data and missed conversions. 

Server-side tracking sends data directly from your server to platforms like Google Ads, Facebook, or Pinterest, so it’s not affected by these blockers. In this setup, server-side acts like a safety net, catching the conversions that client-side may miss.

If one fails, the other might still work. It also future-proofs your setup, considering that privacy regulations and browser changes are happening quickly. Server-side tracking gives you more control over how data is handled and shared, helping with compliance and data consistency across platforms.

When using both client-side and server-side tracking, always configure event deduplication. Without it, the same event might be counted twice - once from the browser and once from the server. Platforms like Facebook and TikTok support deduplication through unique event IDs. 

However, not all platforms offer this (e.g., Google Ads.) If that’s the case with your platform, you’ll need to choose one tracking method (client or server) to avoid overcounting.

Client-side tracking can collect much information about the user. However, server-side tracking is more reliable and lets you enrich the data for a clearer picture. For example, you can add data about orders via phone and other offline conversions, or include order information from payment services like Stripe.