Display a test ad

# Get Started with Google Publisher Tag The Google Publisher Tag (GPT) is an ad tagging library for Google Ad Manager. You can use GPT to dynamically build ad requests. GPT takes key details like the ad unit code, ad size, and custom targeting, builds the request, and displays the ad on web pages. For more details on GPT, see the [Ad Manager help center](https://support.google.com/admanager/answer/181073). Here are some samples you can use to get started with GPT. If you need more help with GPT, see the [support options](https://developers.google.com/publisher-tag/support/feedback-questions). ## Display a test ad The following example walks you through creating a test page that uses GPT to load a generic ad from Google's test network. Full code for this example can be found on the [display a test ad](https://developers.google.com/publisher-tag/samples/display-test-ad) sample page. 1. Create a basic HTML document In a text editor, create a basic HTML document called `hello-gpt.html`. ```html Display a test ad ``` 2. Load the GPT library Load the GPT library by adding the following to the `` of the HTML document. This code loads the GPT library from . Once the library has fully loaded, it processes any queued commands in the [`googletag`](https://developers.google.com/publisher-tag/reference#googletag) object. > [!IMPORTANT] > **Important:** Only [load GPT from a Google domain](https://developers.google.com/publisher-tag/guides/general-best-practices#load_from_an_official_source). ```html Display a test ad ``` 3. Define an ad slot Define an ad slot and initialize GPT using the [`googletag.enableServices()`](https://developers.google.com/publisher-tag/reference#googletag.enableServices) method. This code first ensures the googletag object is available, then queues a command which constructs an ad slot and enables GPT. The ad slot in this example will load an ad of size `300x250` from the ad unit specified by path `/6355419/Travel/Europe/France/Paris`. The ad will be displayed in a `

` element in the body of the page, which will be added next.
> [!IMPORTANT] > Ad unit path follows the format `/network-code/[parent-ad-unit-code/.../]ad-unit-code`, where: > >
> > - network-code is a [unique identifier](https://support.google.com/admanager/answer/7674889#network-code) for the Ad Manager network the ad unit belongs to > - parent-ad-unit-code are the codes of all parent ad units (only applies to non-top level ad units) > - ad-unit-code is the code for the ad unit to be displayed > > Note that all ad unit codes included in the ad unit path must adhere to the > [formatting rules](https://support.google.com/admanager/answer/1628457#ad-unit-codes) specified by > Ad Manager.
```html Display a test ad ``` 4. Specify where the ad will appear Specify where the ad will appear on the page by adding the following code to the `` of the HTML document. Note that the ID of this `

` matches the ID specified when defining the ad slot. ```html ``` 5. Preview the test page Save the `hello-gpt.html` file and open it in a web browser. Once loaded, the page will display a test ad in the body of the web page. > [!CAUTION] > **Caution:** If you don't see an ad, ensure that the div ID specified in the `` of the page matches the ID of the `

` element you added to the `` of the page. ## Display your own ad To display your own ad, use the `hello-gpt.html` file from [Display a test ad](https://developers.google.com/publisher-tag/guides/get-started#generic-ad), then replace the code in the header with code specifying inventory from your own Ad Manager network. > [!NOTE] > **Note:** Before you can display an ad from your Ad Manager network, you need to make sure there's an active line item already trafficked in the "Ready" status. Learn more about creating line items in the [Ad Manager help center](https://support.google.com/admanager/answer/82236). 1. Generate an ad tag for the ad unit you'd like to display. Learn more about generating ad tags in the [Ad Manager help center](https://support.google.com/admanager/answer/177207). 2. Copy the ad tag code provided in the **Document header** section and use it to replace the corresponding code in the `` of your HTML document. > [!CAUTION] > **Caution:** ensure that the width, height, and ID of the `

` declared in the body of the page matches the width, height, and ID of the ad slot defined in the ad tag code. Hello GPT \ window.googletag = window.googletag \|\| {cmd: \[\]}; googletag.cmd.push(function() { googletag .defineSlot("ad-unit-path", \[width, height\], "div-id") .addService(googletag.pubads()); googletag.enableServices(); }); \ 3. Save the updated `hello-gpt.html` file and open it in a web browser.