Google Ads Auto-Tagging: Turn It On and Check It Works

Google Ads auto-tagging adds a click id, the gclid parameter, to your landing page URL when someone clicks your ad, so Google Ads, Google Analytics and offline conversion imports can tie a visit back to the click. You turn it on with one checkbox, and the checks below prove the click id reaches your landing page, survives redirects and forms, and works next to your UTM tags.

Turn it on

Check 1: Is auto-tagging on?

WhereGoogle AdsAdminAccount settingsAuto-tagging

Do: Open the Auto-tagging section.

You should see: The box next to Tag the URL that people click through from my ad is checked. Google calls auto-tagging required for conversion tracking and for offline conversions, and it is on by default for new accounts.

If not: Check the box and click Save.

Careful: Creating a new conversion action turns auto-tagging on by itself, except in accounts that use cross-account conversion tracking. There, Google says to turn it on in each client account yourself.

Follow the click id through your site

Check 2: Does a test click id survive on the landing page?

WhereGoogle AdsCampaignsInsights & reportsLanding pages

Do: Copy a URL from the Landing pages page (Google: landing pages), add Google's test parameter and load it in a new tab. Use ?gclid=TeSter-123, or &gclid=TeSter-123 if the URL already has a ?, and put it before any # (Google: check if auto-tagging works). Then repeat with Google's long value, since a real gclid can be up to 100 characters:

https://www.example.com/landing?gclid=TeSter-123
https://www.example.com/landing?gclid=TeSter-123-ABCDEFGHIJKLMNOPQRSTUVWXYZ-abcdefghijklmnopqrstuvwxyz-0123456789-AaBbCcDdEeFfGgHhIiJjKkLl

You should see: The page loads normally and, once it has finished loading, the address bar still shows the whole test value with its upper and lower case intact.

If not: An error page means the site rejects unknown parameters: Google says to turn auto-tagging off until your developer allows arbitrary URL parameters. A missing value means the site drops query parameters, so look for a redirect in check 3. A lowercased value comes from a URL rewrite rule, and Analytics then reports the visit as google / cpc with campaign, ad group and keyword as (not set). Let the server keep uppercase letters, hyphens and underscores.

Check 3: Does the gclid survive every redirect?

WhereChrome menuMore toolsDeveloper ToolsNetwork

Do: Open the Network tab before you load the test URL from check 2. Click the first requests and look for status 301 or 302 and the Location response header, which shows where the browser went next (Google's redirect test).

You should see: Every Location in the chain still carries gclid=TeSter-123. The redirects to test are your own site's: on Search, Shopping, Display, Video and Performance Max campaigns, parallel tracking is mandatory and sends people straight to the final URL while click measurement runs in the background.

If not: Point the ad's final URL at the page the redirect ends on, or make the server rule carry the query string to the new URL. JavaScript redirects drop the parameters too, so make sure your Google tag fires before any redirect.

Check 4: Does the page keep the click id in a cookie?

WhereDeveloper ToolsApplicationStorageCookies

Do: On the page you loaded with the test URL, select your site's origin and type _gcl in the Filter box (Chrome DevTools: cookies).

You should see: A cookie named _gcl_aw. The Conversion Linker tag reads the click id from the landing page URL and keeps it in _gcl_* cookies on your domain, where Google Ads conversion tags read it when the visitor converts later.

If not: In Google Tag Manager, add a Conversion Linker tag on the All Pages trigger. A container that already loads a Google tag on every page does not need one.

Careful: Consent-aware tags, the Conversion Linker included, do not store cookies while storage consent is denied. If a banner is waiting for a choice, accept it and load the test URL again. How the banner and the tags work together is covered in consent mode v2 in Google Tag Manager.

Check 5: Does the click id reach the form?

Do: Find where your form or booking widget runs: as part of your page, inside an embedded frame (an iframe), or on another domain, such as a form or scheduling tool's own page.

You should see: The form is part of your own page, and the page that confirms a submission is on the same domain. A tag inside an iframe cannot read the gclid from the page address, and Google says not to fire tags from within an iFrame.

If not: For a form in an iframe, keep the tags on the parent page, which is Google's fix. For a form or confirmation page on another domain, carry the click id across with the linker: in the Conversion Linker tag, select Enable linking across domains, list that domain in Auto Link Domains and set Decorate Forms to true. The other domain needs a compatible tag to read it. Calendly has its own route, covered in Calendly tracking for Google Ads and GA4.

Add UTM tags without replacing it

Check 6: Do your UTM tags sit next to the gclid?

WhereGoogle AdsCampaignsCampaignsSettings

Do: If you want UTM tags, click the pencil icon in the campaign's Tracking template column and enter them in the Final URL suffix field, which adds them to the end of the landing page URL. Google suggests UTM tags as a fallback, especially for campaigns where privacy parameters such as wbraid or gbraid may be used.

You should see: The UTM tags and gclid=TeSter-123 both survive when you rerun check 2 with the suffix added to the test URL.

If not: A redirect is dropping them, so fix it as in check 3. Never add the tags through a redirect from the final URL to a tagged URL, which keeps Google Ads data out of Analytics.

Careful: GA4 has no override option. When a URL carries both, it uses the auto-tagged values for source, medium and the other traffic-classification dimensions, and your utm_content and utm_term fill Manual ad content and Manual term. When the gclid cannot be used, GA4 takes every traffic-source value from the UTM tags alone, so set all of them, especially utm_source, utm_medium, utm_campaign, utm_id and utm_source_platform. A missing one shows as (not set).

Confirm with real clicks

Check 7: Does GA4 name your Google Ads campaigns?

WhereGA4ReportsAcquisitionOverview

Do: Once real ad clicks have come in and you have allowed 24 to 48 hours for processing, click View Google Ads campaigns in the Sessions by Session Google Ads campaigns card (Google Ads campaigns report).

You should see: Sessions listed under your campaign names. Some (not set) can remain: iOS clicks from a handful of Google apps carry wbraid instead of a gclid, and GA4 may not name the campaign for them.

If not: No Google Ads data at all means checking the link first, since data cannot flow until GA4 and Google Ads are linked: see how to link GA4 to Google Ads. Paid clicks reported as organic, direct or (not set) can mean auto-tagging is off with no UTM tags behind it (check 1). Sessions from google / cpc with the campaign as (not set) can point to a lowercased gclid (check 2).

Once the click id arrives

When all seven checks pass, your ad clicks reach your site with a click id your tags can keep. Saving that click id with each lead in your CRM, so sales that close offline can go back to Google Ads, is a separate job that starts here. The offline loop I delivered sends Google only a click id, a conversion value and a timestamp, so it cannot work without this step. That loop is what closed-loop attribution covers.

Frequently asked questions

Is Google Ads auto-tagging on by default?

Yes, for new accounts. Google also turns it on when you create a new conversion action, unless the account uses cross-account conversion tracking from a manager account. In that case, turn it on in each client account under Admin, Account settings, Auto-tagging.

Can UTM parameters override auto-tagging in GA4?

No. GA4 has no override option, so when a URL carries both, it uses the auto-tagged values for source, medium and the other traffic-classification dimensions. Your utm_content and utm_term values still fill the Manual ad content and Manual term dimensions.

Why does my landing page show an error when auto-tagging is on?

A small share of sites reject URL parameters they do not recognize and serve an error page once the gclid is added. Google's advice is to turn auto-tagging off, have your web developer allow arbitrary URL parameters, then turn it back on.

Do I still need UTM tags on Google Ads if auto-tagging is on?

Only as a fallback. GA4 uses them when it cannot use the gclid, and Google suggests them for campaigns where privacy parameters such as wbraid or gbraid may be used. If you set one UTM tag, set all of them, because a missing one shows as (not set).