Set up Advertiser cross-device linking

Use the power of your user data to show your Display ads to your users across their devices.

This article explains how to set up the user_id custom parameter in your remarketing tag to enable Advertiser cross-device linking. Note that if you set up user ID remarketing before October 3rd, 2018, you already are opted in to cross-device linking.

Before you begin

The user_id parameter is a unique, anonymous identifier that you should generate and send via the Google Ads remarketing tag that links different devices and browsers for a single user. Learn more About cross-device linking with user ID parameters.

If you're setting up Advertiser cross-device linking, you need to comply with the Advertiser cross-device linking policy. Unless you set up cross-device linking before October 3rd, 2018, you’ll need to contact your Google sales manager to whitelist your account for cross-device linking.


The new Google Ads experience is now the exclusive way for most users to manage their accounts. Note, automatic targeting is only available in the new Google Ads experience.

Set up the cross-device parameter in your remarketing tag

  1. Create a new remarketing tag or choose an existing tag to modify to pass the user ID information. Learn how to Tag your site for remarketing
  2. Modify your tag to pass cross device parameter. Learn how to Tag your site for dynamic remarketing
  3. Create a parameter named google_user_id to pass the user ID


When assigning user IDs, there are three important things to remember:

  1. Each user must have a unique user ID. 
  2. For each user, the user ID parameter must be the same each time they visit your website. For example, if Mary visits your website in the morning and then your mobile website in the afternoon, you must provide the same user ID for both instances.
  3. You may not pass Google personally identifiable information (PII) in the user ID.

Your tag should now look something like the one below:

<!-- Google Code for Main List -->
<!-- Remarketing tags may not be associated with personally identifiable information or placed on pages related to sensitive categories. For instructions on adding this tag and more information on the above requirements, read the setup guide: -->
<script type="text/javascript">
/* <![CDATA[ */
var google_conversion_id = 1010101010;
var google_remarketing_only = true;
var google_user_id = '<unique user id>';
/* ]]> */
<script type="text/javascript" src="//">
<div style="display:inline;">
<img height="1" width="1" style="border-style:none;" alt="" src="//;label=eiULCI6v9wIQitem-gM&amp;guid=ON&amp;script=0&amp;userId=<unique user id>"/>

Verify your setup

To make sure your user ID parameters are set up correctly for Advertiser cross-device linking:

  1. Confirm that the google_user_id parameter is firing wherever your tag is active — desktop website and mobile site. This is how AdWords makes links between devices and browsers. 
  2. Make sure the google_user_id parameter is firing, and sending unique IDs for each user. 
  3. Go to the Shared Library section in your AdWords account then click on Audiences.
  4. Click on the remarketing tag and verify that the google_user_id parameter and Advertiser cross-device linking are active.

Opt-in to Advertiser cross-device linking

If you did not setup up cross-device linking before October 3rd, 2018 and would like to you'll need to contact your Google sales manager.

Note: Adding user_id parameter in your remarketing tag and sending user_id parameter values are not sufficient for enabling cross-device linking.

Was this helpful?
How can we improve it?
Previous New

Need more help?

Sign in for additional support options to quickly solve your issue