Verification & Troubleshooting

Once you have implemented your tags on your site, it is important to verify that they are firing correctly and troubleshoot any issues found. If you are using dynamic remarketing you should also make sure that your parameter names exactly match those in the parameter reference.

Verification Using AdWords

If you have setup your tags and begun to receive traffic on the pages that have the Remarketing Tag on them then you can do some basic tag validation right from inside of the AdWords UI itself. This approach is simple, but there is a lag of up to 15 minutes before verification data will be visible inside of the AdWords UI.

Full details about this approach can be found on the Remarketing tag validations and alerts page in the AdWords help centre.

Verification using Google Tag Assistant

Google Tag Assistant is a free extension for the Google Chrome browser that allows you to quickly check the implementation status of the AdWords Remarketing Tag as well as other Google tags such as tags from Google Analytics and DoubleClick Floodlights. Figure 1 shows an example of the output from the Google Tag Assistant when loading a page that contains a functioning remarketing tag that has sent a request. Figure 2 shows details of the parameters that were sent in the remarketing tag sent.

The tags that fired are shown by Google Tag Assistant
Figure 1: Example of a Google Tag Assistant showing successful firing of the Remarketing Tag
The parameters passed during the firing of the remarketing tag are shown by Google Tag Assistant
Figure 2: Example of a Google Tag Assistant showing details of the remarketing parameters sent by the Remarketing Tag

Google Tag Assistant can be installed from the Chrome Web Store's page. Once installed Google Tag Assistant will offer status indicators and context-sensitive help for specific problems it finds with your implementations. Additional help can be found in the Google Tag Assistant help centre.

Verification using browser-based developer tools

Most modern browsers now include detailed developer tools that can help us to verify the correct operation of the remarketing tag by letting us monitor the HTTP requests that are made by the browser.

When perfoming this style of verification we can use these developer tools to check that the remarketing tag is making a HTTP request to googleads.g.doubleclick.net with the correct parameters, and that it gets a suitable response back from the server. We explain how to perform this level of verification for both Google Chrome and Mozilla Firefox below - other common browsers such as Safari and Internet Explorer have similar functionality but the exact steps will vary.

Troubleshooting Common Tag Firing Problems

No request seen in developer tools

This could simply be that the tag is not present on the page when it was loaded - if you are using a tag management solution make sure that its firing rules are correct, or if you are directly implementing the tag on your page you can view the source of the page and look for the tag itself.

Another common problem is a javascript error in the page that is causing the browser to abort execution of the javascript. The easiest way to check for this is to look in the "Console" tab of the developer tools and look for any javascript errors and address those before checking again.

Missing data parameter

If you are not passing any custom parameters in the remarketing tag then the data parameter will not be sent at all. If however you intended to send custom parameters then double check to make sure that the parameters are included in the page and that the parameter names for the custom parameter snippet and the reference to that snippet in the main body of the tag match, otherwise the parameters will be treated as undefined.

Unexpected HTTP response codes

If you get a response code other than 302 from the remarketing tag's HTTP request then there may be a problem with the implementation. In this case you should double check that the tag has not become malformed during implementation.

If you have a particularly large number of custom parameters and a particularly long URL then you may receive a HTTP response of 414 or 400 when the remarketing tag fires and the final URL for the request is longer than 2048 characters. Although an error is returned in this case, the remarketing request is still processed, but some information may be lost if it has been truncated. The URL and Referer URL sent in the request are truncated to 512 characters and will be the first parameters to be truncated, followed by the more critical parameters in the request.

If you are seeing this error when verifying your remarketing tag we'd recommend revisiting the custom parameters you are sending - some options include changing the names of the parameters to shorter names and not sending parameters if they have a null or undefined value.

Troubleshooting Common Syntax Problems

google_tag_params Syntax Problems

Below are some common mistakes and problems encountered by advertisers implementing the google_tag_params when running dynamic remarketing.

IncorrectSolution
Trailing commas in google_tag_params object
var google_tag_params = {
  parameter1: 'abc123', 
  parameter2: 29.99,
};
The code has a trailing comma at the end of parameter2 which means it is invalid javascript syntax and will cause javascript errors. The trailing comma should be removed:
var google_tag_params = {
  parameter1: 'abc123', 
  parameter2: 29.99
};
Unquoted strings
var google_tag_params = {
  parameter1: abc123, 
  parameter2: 29.99
};
The value for parameter1 is not properly quoted meaning that javascript is trying to treat it as a reference to a variable previously declared asabc123, but as it was not previously declared it is undefined it will cause javascript errors. The string should be quoted:
var google_tag_params = {
  parameter1: 'abc123', 
  parameter2: 29.99
};
Missing property value
var google_tag_params = {
  parameter1:, 
  parameter2: 29.99
};
The value for parameter1 has not been provided resulting in invalid javascript syntax and will cause javascript errors. The parameter should not be provided at all if it has no value
var google_tag_params = {
  parameter2: 29.99
};
Missing array notation for multiple values
var google_tag_params = {
  parameter1: 'abc123', 'def456', 
  parameter2: 29.99
};
The value for parameter1 has multiple values but has not been provided as an array. If the parameter's should contain more than one value then it should be provided as an array using standard javascript notation
var google_tag_params = {
  parameter1: ['abc123', 'def456'],
  parameter2: 29.99
};
Array of values passed as a string
var google_tag_params = {
  parameter1: '[abc123, def456]', 
  parameter2: 29.99
};
The value for parameter1 has been provided as a javascript string and not an array. If the parameter's should contain more than one value then it should be provided as an array using standard javascript notation
var google_tag_params = {
  parameter1: ['abc123','def456'],
  parameter2: 29.99
};
Object properties terminated by semi-colon
var google_tag_params = {
  parameter1: 'abc123'; 
  parameter2: 29.99;
};
The google_tag_params object's properties are terminated by a semi-colon which is invalid javascript syntax and which will cause javascript errors. The google_tag_params object should be described using standard javascript object literal notation
var google_tag_params = {
  parameter1: 'abc123',
  parameter2: 29.99
};