• Configuration checklist
• Discrepancies in Clicks and Sessions
• Discrepancies in the Conversion Rate
• Related resource

There are a number of reasons why Google Ads and Analytics may report different numbers of clicks and sessions:

• Clicks and Sessions are different metrics.
  Google Ads tracks Clicks, while Analytics tracks Sessions. If a user clicks on your ad twice within thirty minutes without closing his or her browser, this is registered by Analytics as one session, even if the user left your site and then returned shortly after. For example, if a user clicks on your ad once, clicks the back button, and then clicks your ad again, Google Ads registers two clicks while Analytics registers one session.
• Google Ads filters invalid clicks from your report, while Analytics shows all data.
  Google Ads automatically filters certain clicks from your reports, while Analytics reports on all the resulting sessions. The clicks we filter from your Google Ads reports are the occasional instances of someone clicking repeatedly on your ad in order to increase your costs or to increase your clickthrough rate. Google Ads considers these clicks to be invalid and automatically filters them from your Google Ads reports. You are not charged for these potentially invalid clicks.
• You turned off auto-tagging for your URLs in your Google Ads account.
  If auto-tagging is turned off, and you did not manually tag the final URLs with campaign tracking variables, the traffic is not marked as Google CPC (clicks that came through from Google Ads ads), but instead may be attributed to Google Organic (clicks from organic search results on Google.com). Ensure that your Google Ads account either has auto-tagging turned on or has campaign tracking variables appended to the end of every final URL.
  
  Learn how to enable autotagging.
• Make sure your Google Ads Import & Export Settings are correct.
  If you are sure the accounts are linked and you still do not see click or cost data, check to make sure that you have selected the option to import the data from the linked account to the view in question.
  
  Learn how to edit your Google Ads Import & Export Settings
• Your site has a server side URL rewrite
  Adding additional parameters to your URL may cause your rewrite rule to break. A small percentage of websites do not allow arbitrary parameters in the URL and consequently serve error pages when you include those parameters. We suggest that you lobby your webmaster to allow arbitrary URL parameters.
• Your landing page might redirect to a different page.
  Redirects in landing pages can often keep the Analytics code from launching and properly identifying the traffic as having come from a paid search campaign. For example, if your ad leads to http://www.mydomain.com/index.html, but you've created a 301, 302, or JavaScript redirect from that URL to http://www.mydomain.com/page2.html, the campaign information that was originally appended to the landing page is lost upon redirection.
  
  Learn how to track redirecting pages.
• Make sure the landing page for your ads is being tracked.
  If the landing page for your ads is not being tracked, your campaign information is not passed to Analytics. Ensure that you are tracking all landing pages for your Google ads.
• Users might have set their browser preferences in ways that prevent Analytics used on websites from collecting data.
  Users entering your website through Google Ads might have JavaScript or images turned off, or might use other technologies preventing Analytics from reporting about your website users (such as by installing the Analytics opt-out browser add-on). In some cases, Analytics might not be able to report these users, but they are reported through Google Ads.
• Make sure your landing page is able to load the code properly.
  Clicks reported on Google Ads but not on Analytics may be the result of an obstruction between the Google Ads click event and the ability to load the tracking code on the landing page. If this is the case, ensure that your web hosting servers are functioning properly, the page is loading for all possible users and IPs, and the tracking code is installed correctly on your web pages.
  
  Learn how to check that you've installed the Analytics code properly. 
• Users return during the lifetime of a campaign.
  During the lifetime of a given campaign, a returning user to your site is attributed to that one campaign. In such cases, you can expect to see more sessions than clicks. To see the number sessions from returning users, cross-segment the campaign by User Type.
• Users return to your site via bookmarks.
  Analytics uses the gclid parameter in your final URLs to identify traffic from Google Ads ads. The gclid parameter shows up in your landing page URL when a user arrives at your site from your ad. For example, if your site is www.example.com, when a user clicks on your ad, it appears in the address bar as:
  
  www.example.com/?gclid=123xyz
  
  If users bookmark your website along with the gclid parameter, Analytics records traffic from these bookmarks arriving from your Google Ads ads. However, Google Ads doesn't record the clicks (and advertisers are not charged for these sessions since they're not actual clicks on the ads).
• Server latency
  If a user comes to your site from an ad, and then leaves the landing page before the tracking code executes, then the gclid parameter is never passed to the Google servers, and that click is not associated with the session. The result is a clicks vs. sessions discrepancy.

In Analytics, Conversion Rate is the percentage of users that convert on at least one of the Goals you have defined for that view. This is different than the Google Ads Conversion Rate you see in your Google Ads account. In Google Ads, the Conversion Rate refers to the percent of clicks that end in a Google Ads conversion, defined by the Google Ads Conversion Tracking code. Please refer to the following article for more information on the differences between these two types of conversion tracking.