A tool in your account that helps identify why your ad or ad extension might not be appearing. The tool also shows a preview of a Google search result page for a specific term. This helps you see which ads and extensions are appearing for your keyword. Once you enter a search term and other criteria like language and location, the tool will tell you whether your ad is eligible to appear in that situation.

• The Ad Preview and Diagnosis tool suggests search term auto-completions as you type. Suggestions come from keywords with impressions in your account, and are ordered by volume.
• Use this tool to check if your ad extension is showing with an ad for a particular keyword. If any of your extensions aren't showing, the tool will tell you what might be causing them not to show.
• Use the 'Share this search' feature to bookmark specific searches or to send the URL to colleagues or clients so they can view Google search results for this particular search as well. Keep in mind that the search results returned by this tool may change over time. For example, a preview of your ad may no longer appear in the tool when your campaign reaches its daily budget.

​If you want to see how your ad appears in search results, it's better to use this tool than to do a search on Google. You'll see the exact same results as a Google search but it won't affect your performance stats by accumulating ad impressions every time you search for your ad.

* Nguồn: Google