About User ID remarketing

You can create User ID remarketing lists by uploading customer segments keyed on custom generated user IDs. These user ID lists are eligible for targeting across Google properties, including Search, Shopping, and YouTube.


Here are some of the benefits of using User ID lists for remarketing:

  • Advantages over Customer Match
    • User ID remarketing lists increase targeting coverage to signed-out traffic for Search and YouTube.
  • Advantages over RLSA
    • Offline segmentation: Savvy advertisers have robust offline backend systems to build highly tailored segments from their CRM data. These segments utilize both historic and dynamic attributes, which can’t always be passed via the RLSA pings.
    • Post-facto state management: RLSA is dependent on page views to drive list changes. Therefore, targeting newly identified customer segments would require the user to visit the advertiser website first (in order to be added to a new RLSA list).

How User ID remarketing works

To implement a User ID remarketing list, add a top-level parameter called "user_id" to your remarketing tag (this value is non-PII). User_id is a unique identifier that you internally associate with a certain customer. With this parameter, an advertiser can add a User ID Tag to collect User Lists that are matched to the Google cookie space without providing personally identifiable information (PII) to Google. When that customer visits your website, the g Tag javascript embedded in the website passes the user_id to Google, enabling Google to associate the given “user_id” with the user’s Google cookies. This association lets you to build User ID remarketing lists by uploading lists of user_ids via the Google Ads UI or API.

Note: User ID remarketing in Google Ads does not work with the Google Analytics tag and its own User-ID functionality.

Option 1: Set up the User ID parameter in your remarketing tag yourself

  1. Sign in to your Google Ads account.
  2. Click the tools icon Google Ads | tools [Icon] in the upper right-hand corner of your account.
  3. Under "Shared library", click Audience manager.
  4. Click Audience sources from the page menu.
  5. Click the 3-dot icon 3 dot icon next to "Google Ads tag".
  6. Click Edit source to set up a Google Ads tag.
  7. Click Advanced settings then select the “user_id” checkbox. The user_id checkbox may be grayed out if you are not on the Customer Match allowlist. Learn More
  8. Click Save and Continue.
  9. If you haven't already installed the gtag.js global site tag on your site, follow these instructions to implement it.
  10. Implement the event snippet to pass the user_id parameter when users log in or register on your website (or on any page where you have access to a stable user_id for the current user). See additional instructions below.

You are responsible for generating user_id values for every user and ensuring that those values are stable and consistent for each user across sessions, browsers, and devices.

Usually, this can be achieved if your website offers a user account functionality letting users register and sign in. Upon registration, you should generate a unique identifier for the user and pass it to Google Ads via the tag. When the same user comes back to your site and signs-in again, you should pass the same identifier again via the user_id parameter.

An example of a way to pass the user_id parameter via gtag.js is shown below:

<script>gtag('event', 'login', { 'user_id': '132456' });</script>

The sample snippet above uses “login” as event name, but you can pass any event name that you want. The only requirement is to include “user_id” as part of the event data argument.

Note that if you have already implemented the event snippet on certain pages of your site (for instance, to capture dynamic remarketing parameters), you may add the user_id parameter to your existing event snippets, as shown here:


gtag('event', 'page_view', {

'send_to': 'AW-CONVERSION_ID',

'user_id': 'replace with value',

'value': 'replace with value',

'items': [{

'id': 'replace with value',

'google_business_vertical': 'retail'





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 when they visit your website. For example, if Mary visits your website in the morning and you upload the user_id to create User ID remarketing lists via the Google Ads upload API, you must provide the same user_id for both cases.
  3. You may not pass Google personally identifiable information (PII) in the user_id.

Option 2: Set up the User ID parameter in Google Tag Manager

Google Tag Manager is a tag management system that allows you to quickly and easily update tags and code snippets on your website. You can use Google Tag Manager to install your Google Ads Remarketing tag.

  1. Sign in to your Tag Manager account.
  2. Select Tags.
  3. Click on the Remarketing tag name you want to edit.
  4. Set your user ID variable.
  5. Click Save to complete your tag setup.
  6. Preview and confirm your changes, then click Publish.

Upload “user_ids” data using the Google Ads API (AdWords API)

Account owners or administrators can use the Google Ads API (AdWords API) to upload data files of “user_ids” and manage their User ID remarketing audiences. Advertisers can upload a data file, add or remove customer data, or edit configurations through the API. To learn more, visit the remarketing section of the Google Ads API (AdWords API) in the Google Developers website.

User ID data are not considered PII data, and it is strongly recommended that advertisers hash User ID data before uploading to Google. Make sure that User IDs uploaded are identical to those sent to Google in the remarketing tag.

The user_id parameter can also be used for Google Ads 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. Learn more about Advertiser cross-device linking

Note: Tag must be from the Google Ads account (or from linked Google Ads manager accounts) uploading User IDs.
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