Add the dynamic remarketing tag to your site

About dynamic remarketing

Dynamic remarketing lets you reach your past site visitors with ads that show the specific products people viewed on your site. Once you've set up your dynamic remarketing campaign, you'll need to add the dynamic remarketing tag, including custom parameters, to your site so your lists can start working.

Your remarketing tag shouldn't be associated with any personally identifiable or sensitive information. Sensitive categories of sites can't use remarketing. If you're setting up a remarketing campaign and placing the remarketing tag on your site, you need to follow the Policy for advertising based on interests and location.

Click the links below to learn how to implement, validate, and customize the dynamic remarketing tag:

• Place the tag on your site with custom parameters that are needed for dynamic remarketing
• Check that the tag is working correctly and learn about common errors
• Customize the tag to reach the right visitors and to optimize your bids

Place the tag on your site with custom parameters

You need to add the dynamic remarketing tag (snippet of code) on every page of your site. The tag will collect the product id and the type of page people visited (product page, shopping cart page, purchase page, general site visit).

Below is an example of how the dynamic remarketing tag might look. This isn't the exact snippet of code you should add to your site. Learn where to find your remarketing tag.

The section in green font (that ends with the </script> tag below ecomm_totalvalue: 'REPLACE_WITH_VALUE') includes the custom parameters, and the section in blue font (that ends with the </noscript> tag) includes the remarketing tag.

• The tag must be implemented on all pages (added just before </body> tag) of your website.
• Custom parameters are the only way to dynamically send values to your AdWords account (for example, product ID, page type, total value) based on information on the page.

Important notes:

• The code should use JSON format: JavaScript Object Notation, a format for transmitting structured data over a network connection.
• You should use at least ecomm_prodid, ecomm_pagetype, and ecomm_totalvalue as your custom parameter keys for the lists to start working correctly.
• On pages that have multiple Product IDs (for example, the shopping cart page), you can group them using brackets. Example: ecomm_prodid: ['123', '456']
• You can either use single or double quotes in the custom parameters. Both will work, but you have to be consistent. If you choose to use single quotes, use them for all values.
• Don't forget to include a comma to separate the parameters. If you don't include commas, the tag won't work properly. See common errors in the dynamic remarketing tag setup and find out about how Google Tag Assistant can help you check for these common errors. (Note: This help article is available in English only.)

Custom parameters

Basic parameters

Validate that the tag is working correctly and learn about common errors

There are two ways that you should validate your tag:

• Google Tag Assistant: During tag implementation, you can use Google Tag Assistant to validate on each page that your tag is working properly. (Note: This help article is available in English only.) Google Tag Assistant will catch most syntax errors, and can also validate if the product ID you're using matches the ID in your Google Merchant Center account. Download Tag Assistant from the Chrome web store.
• The "Remarketing tag" section in AdWords: After you've added the tag across your site, you can visit the "Audiences" section of the Shared Library in your AdWords account to validate your remarketing tag. In the "Remarketing tag" box at the top of the page, you'll find information about your tag, such as implementation problems or any opportunities to further optimize your setup.

For example, you might discover that some of the product IDs you send through the tag don’t have a matching entry in the Google Merchant Center; this would mean that you're losing a valuable opportunity to serve an effective dynamic ad. Tag validation will give you guidance on how to address this and other tag issues.

You can use Google Tag Manager to implement the dynamic remarketing tag. Learn more about Google Tag Manager.

Common errors when setting up custom parameters

Below are some of the common mistakes people make when they implement custom parameters. If you use Tag Assistant, you'll be able to identify most of these common mistakes.

1. String values are not quoted. For example:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 2234,
ecomm_pagetype: purchase,
ecomm_totalvalue: 120.99
};
</script>

   Should be changed to:

   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 2234,
ecomm_pagetype: "purchase",
ecomm_totalvalue: 120.99
};
</script>

   Single quotes also work, as long as they are used consistently. Numbers don't need quotes.

2. Custom parameters are not separated by a comma (","). For example:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 234
ecomm_pagetype: "purchase"
ecomm_totalvalue: 120.99
};
</script>

   Should be changed to:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 234,
ecomm_pagetype: "purchase",
ecomm_totalvalue: 120.99
};
</script>

   The last custom parameter doesn't need to have "," after it. But it's OK if it does.

3. Parameter contains space or non-ASCII characters. We only support [a-z][0-9] and '_'. For example:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 234,
ecomm pagetype: "purchase",
ecomm_totalvalue: 120.99
};
</script>

   Should be changed to:

   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 234,
ecomm_pagetype: "purchase",
ecomm_totalvalue: 120.99
};
</script>
4. Multiple values in a parameter without brackets. For example:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: "123,"234",
ecomm_pagetype: "cart",
ecomm_totalvalue: 100,50
};
</script>

   Should be changed to:

   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: ["123","234"],
ecomm_pagetype: "cart",
ecomm_totalvalue: [100,50]
};
</script>
5. Parameter with no value. For example:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: ,
ecomm_pagetype: "other",
ecomm_totalvalue:
};
</script>


   Should be changed to:
   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: "",
ecomm_pagetype: "other",
ecomm_totalvalue: ""
};
</script>

   or simply:

   <script type="text/javascript">
var google_tag_params = {
ecomm_pagetype: "other"
};
</script>
6. Incorrect naming convention for custom parameters. For example:
   <script type="text/javascript">
var google_tag_params = {
pid: 2234,
pagetype: "purchase",
totalvalue: 120.99
};
</script>

   Should be changed to:

   <script type="text/javascript">
var google_tag_params = {
ecomm_prodid: 2234,
ecomm_pagetype: "purchase",
ecomm_totalvalue: 120.99
};
</script>

Customize the tag to reach the right visitors and to optimize your bids