Why do the page title and screen class show “(not set)” in GA4?

Short Answer

You will see the page title and screen class as “(not set)” because the <title> tag is empty on your webpage.

Quick Fix

You should always fill your <title> tag with content. If you do this, you won’t see the “(not set)” value in your page title dimension inside your Google Analytics 4 reports.

For reference, this is how an empty <title> tag looks in your page HTML:

<title></title>

And this is one example of how your title tag should look like:

<title>This is my page title</title>

Detailed answer

On each event, Google Analytics 4 extracts and sends multiple parameters in the data payload to track different details. This includes page views. As the official documentation explains, the “(not set value)” is a placeholder, for that reason, whenever GA4 doesn’t find a specific value on one specific dimension, it will fill that missing value with “(not set)”.

You can quickly check for missing values in your payloads using the official Google Tag Assistant tool or the Analytics Debugger tool developed by David Vallejo which is the recommended tool.