Client-side vs server-side tracking: plain English
If your ad conversions look lower than they should, tracking is probably broken. Here's what's happening and why server-side tracking fixes it.
Why your conversions are disappearing
When someone clicks your ad and buys something, a tiny piece of code – a pixel – is supposed to fire in their browser and tell your advertising and tracking platforms "sale happened." That's client-side tracking. It worked fine for 20 years.
The problem: browsers and ad blockers now block these pixels. Safari has been doing it since 2017. Firefox and other browsers block by default. Around 40% of users have ad blockers installed. The result? Conversions happen, but your ad platforms never find out which negatively impacts your optimization.
On average, businesses lose 25–40% of their tracked conversions to browser restrictions and ad blockers.
Side by side
How the two approaches actually work.
| Client-side | Server-side | |
|---|---|---|
| Where it runs | In the visitor's browser | On your server, then sent directly to ad platforms |
| Ad blockers | Blocked | Not affected |
| Safari / Firefox | Blocked or capped to 7 days | Works fully |
| iOS 14+ impact | Significant signal loss | Largely recovered |
| Data accuracy | 60–75% of actual conversions | 90–98% of actual conversions |
| What ad algorithms see | Incomplete picture – optimizes on bad data | Full picture – algorithms find real buyers |
| Setup | Copy/paste pixel code – minutes | 10 minutes with Tiide |
What this means for your campaigns
Your ROAS looks worse than it is
If 30% of your conversions are invisible, your cost-per-acquisition looks 30% higher than reality. You might be pausing profitable campaigns because the numbers don't add up.
Algorithms optimise for the wrong people
Your ad platforms' algorithms learn from your conversion signals. Feed them incomplete data and they'll find you cheaper-to-track audiences – not higher-value buyers.
Server-side closes the gap
By sending conversion events from your server directly to your ad platforms, you bypass ad blockers and browser restrictions entirely. The data gets through regardless of any ad blockers or what browser, device or privacy extension someone is using.
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