Google Ads

What Is Google Ads (Conversion & Remarketing)?

Google Ads conversion and remarketing tracking is the measurement layer advertisers use to find out whether the money they spend on Google's ad platform actually produces results. When an advertiser runs Search, Display, Shopping, YouTube, or Performance Max campaigns, the ads themselves are only half the system. The other half is a small piece of tracking code on the advertiser's website that reports back what visitors did after they clicked, did they buy, sign up, call, or book, and that builds audiences of past visitors so the advertiser can show them ads again later. That second half is what you are detecting when you find Google Ads tags on a site.

This technology is everywhere because Google Ads is the dominant paid-search platform, and conversion tracking is effectively mandatory to run profitable campaigns. Without it, an advertiser is bidding blind. According to Google's own advertising guidance, conversion tracking is the foundation of smart bidding and campaign optimization, the automated bid strategies literally cannot work well without conversion data flowing back. As a result, virtually any business actively buying Google traffic will have these tags installed, which is why they show up constantly when you analyze a commercial website's technology stack.

It is important to distinguish Google Ads tracking from two neighbours. It is not Google Analytics (that is measurement of all traffic, not just ad-driven conversions), and it is not Google AdSense (that is publishers earning money by showing ads). Google Ads conversion and remarketing tags are advertiser-side: they exist to measure and optimize ad spend and to retarget visitors.

How Google Ads Conversion & Remarketing Works

The modern implementation centers on a conversion ID and conversion labels, delivered through Google's global site tag (gtag.js) or, very commonly, through Google Tag Manager.

Every Google Ads account has a unique conversion ID in the form AW- followed by a string of digits. This is the advertiser's measurement identifier. Each specific conversion action the advertiser defines, a purchase, a lead form submission, a phone call, gets its own conversion label tied to that AW- ID.

There are two main moving parts:

Remarketing tag. This fires on every page load and tells Google "this visitor was here." Over time it accumulates an audience list of people who visited the site (or specific sections of it). The advertiser can then target ads specifically at those past visitors across Google's network and YouTube. The remarketing tag is what makes products seem to follow you around the web after you browse a store.

Conversion tag. This fires on a specific completion event, typically a thank-you or order-confirmation page, or in response to a button click. It reports the conversion back to Google along with optional values like purchase amount and order ID. This is how Google attributes a sale to the click that drove it.

When a visitor clicks a Google ad, Google appends a click identifier, the gclid (or wbraid/gbraid on iOS), to the landing page URL. The conversion tag reads contextual signals and, combined with that click ID, lets Google match the later conversion back to the originating ad, keyword, and campaign. This closed loop powers Google's automated bidding, which adjusts bids in real time to win the clicks most likely to convert.

In practice, most sites deploy these tags through Google Tag Manager (GTM) rather than hard-coding gtag. GTM acts as a container that fires the Google Ads tags based on triggers (page views, clicks, form submissions), which is why detecting GTM is often the first clue that Google Ads tracking is present underneath. Our walkthrough on how to check if a website uses Google Tag Manager covers that layer in detail.

Google has also moved much of this measurement toward privacy-aware models. Consent Mode lets the tags adjust their behaviour based on the visitor's consent choices, sending modeled or cookieless pings when consent is withheld so that bidding still receives some signal. Enhanced conversions improve accuracy by sending hashed first-party data, such as an email address captured at checkout, which Google matches to signed-in users without exposing raw personal data. And server-side tagging is increasingly used, where the conversion event is forwarded from the advertiser's own server-side GTM container rather than directly from the browser, which changes the network fingerprint you will see. These shifts mean that the absence of a classic browser beacon does not always mean the absence of Google Ads tracking; the signal may simply be travelling through a different path.

Because the conversion and remarketing tags share the same AW- account ID, a single Google Ads account often powers both functions on one site: every page fires the remarketing tag to build audiences, while specific completion pages or button clicks fire conversion tags. This is why you frequently see the same AW- identifier referenced in multiple places in a page's code.

How to Tell if a Website Uses Google Ads Tracking

Google Ads tags are slightly more subtle than AdSense because they are about measurement, not visible ads, but they still leave concrete fingerprints.

View Source / DevTools Elements. Search the HTML for AW-. The conversion ID appears in the gtag configuration, for example gtag('config', 'AW-XXXXXXXXX') or inside a gtag('event', 'conversion', {'send_to': 'AW-XXXXXXXXX/label'}) call. Finding an AW- identifier is the clearest single proof of Google Ads tracking. You may also see the global site tag loaded from googletagmanager.com/gtag/js.

DevTools Network panel. This is the most reliable method because the tags fire network beacons. Reload with Network open and filter for:

• googleads.g.doubleclick.net/pagead/viewthroughconversion/ — remarketing and view-through conversion pings.
• googleadservices.com/pagead/conversion — conversion tracking requests carrying the conversion ID and label.
• google.com/pagead/ or googletagmanager.com — supporting requests.

Seeing requests to googleadservices.com/pagead/conversion/XXXXXXXXX/ confirms both that the tag is live and which conversion ID is in use.

DevTools Console. Type dataLayer and inspect it; if the site uses GTM you will see the data-layer array, often containing events that feed the Google Ads tags. Typing google_tag_manager or checking window.google_trackConversion can also reveal the conversion plumbing.

Check the landing-page URL. Click a paid Google result and look at the URL, the presence of a gclid= parameter indicates the page is set up to receive Google Ads click tracking.

curl. Fetch the page body with curl -s https://example.com | grep -iE "AW-|googleadservices|viewthroughconversion" to surface server-rendered tag references. Note that GTM-injected tags load client-side, so curl may only show the GTM container snippet (GTM-XXXXXXX) rather than the Google Ads tag itself; in that case the Network panel is the better tool.

Cookies. Google Ads/remarketing may set cookies on doubleclick.net and a first-party _gcl_aw cookie that stores the click ID for cross-session conversion attribution. Seeing _gcl_aw in the cookie jar is a strong remarketing signal.

Wappalyzer and BuiltWith. Both flag Google Ads conversion tracking and remarketing when they detect the conversion endpoints or the AW- identifier. They are a quick first pass, and our broader guide on how to find out what technology a website uses explains how to layer these tools for confidence.

Because so much of this fires client-side through GTM, a server-side scanner that executes the page and watches network traffic gives a far more dependable read than source-only inspection.

Key Features

• Conversion tracking. Measures purchases, leads, sign-ups, calls, and custom events and attributes them to ad clicks.
• Remarketing audiences. Builds lists of past visitors for targeted re-engagement across Search, Display, and YouTube.
• Enhanced conversions. Sends hashed first-party data (like email) to improve attribution accuracy where cookies fall short.
• Conversion values. Passes dynamic revenue amounts so smart bidding can optimize for value, not just volume.
• Cross-device and view-through tracking. Connects conversions across devices and counts impressions that influenced a later action.
• GTM integration. Deploys and manages tags without editing site code directly.
• Smart bidding fuel. Provides the conversion signal that powers Target CPA, Target ROAS, and Maximize Conversions strategies.
• Dynamic remarketing. Shows visitors the specific products they viewed, common on e-commerce sites.

Pros and Cons

Pros

• Essential visibility into which ads, keywords, and campaigns drive real business results.
• Unlocks automated bidding, which dramatically improves campaign efficiency.
• Remarketing recovers visitors who did not convert on the first visit.
• Enhanced conversions and value tracking sharpen optimization beyond simple click counts.
• Manageable through GTM without ongoing developer work.

Cons

• Adds third-party tracking that raises privacy and consent-compliance obligations (GDPR, ePrivacy, consent mode).
• Attribution can be imperfect due to cookie restrictions, ad blockers, and cross-device gaps.
• Misconfigured tags (double-firing, wrong labels) produce misleading data and wasted spend.
• Remarketing can feel intrusive to users and requires clear disclosure.
• Reliance on Google's ecosystem creates platform lock-in.

Google Ads Tracking vs Alternatives

Google Ads conversion tracking competes and coexists with other ad-platform pixels and measurement tools. Most performance advertisers run several simultaneously.

Technology	Primary platform	Detection signal	Strength	Privacy posture
Google Ads conversion/remarketing	Google Search, Display, YouTube	AW- ID, googleadservices.com	Deepest Search optimization	Consent mode, cookie-based + enhanced conversions
Meta Pixel	Facebook / Instagram	fbq(), connect.facebook.net	Strong social remarketing	Cookie + CAPI server-side
Microsoft Advertising UET	Bing / Microsoft Search	uetq, bat.bing.com	Bing/LinkedIn audiences	Cookie-based
Google Analytics 4	Cross-channel measurement	G- ID, gtag	Holistic traffic analysis	Consent mode, event-based
LinkedIn Insight Tag	LinkedIn	_linkedin_data_partner_id	B2B audience targeting	Cookie-based

The distinction that matters: Google Analytics measures all traffic and behaviour, while Google Ads tags measure ad-driven conversions and build remarketing pools specifically for buying media. They are complementary and frequently installed together via the same GTM container. If a site monetizes content rather than buys traffic, you will instead find Google AdSense, which is the publisher-side counterpart.

Common Use Cases

• E-commerce stores tracking purchases and revenue to optimize Shopping and Performance Max campaigns.
• Lead-generation businesses (services, SaaS, B2B) measuring form fills and demo requests as conversions.
• Local businesses tracking phone calls and direction requests driven by Search ads.
• Dynamic remarketing on retail sites, re-showing exact products visitors browsed but did not buy.
• App and subscription sites measuring sign-ups and trials to feed value-based bidding.
• Multi-channel advertisers combining Google Ads tags with Meta and Microsoft pixels for full-funnel attribution.

Frequently Asked Questions

What does an AW- number mean on a website?

The AW-XXXXXXXXX value is a Google Ads conversion ID. It identifies the advertiser's Google Ads account and ties page activity to their campaigns. When you see it in gtag code or in a send_to parameter, the site is running Google Ads conversion tracking, remarketing, or both.

How is Google Ads tracking different from Google Analytics?

Google Analytics (which uses a G- measurement ID) measures all site traffic and user behaviour across channels. Google Ads tracking (which uses an AW- ID) specifically measures conversions from ad clicks and builds remarketing audiences for buying ads. Many sites run both, often through the same Google Tag Manager container.

Why can't curl always detect Google Ads tags?

Because the tags are frequently deployed through Google Tag Manager, which injects them client-side after the page loads. A curl -s request only returns the initial server HTML, so you may see the GTM container ID (GTM-XXXXXXX) but not the Google Ads tag it fires. Watching the Network panel for requests to googleadservices.com/pagead/conversion is more reliable.

What network requests prove Google Ads conversion tracking is active?

Look in DevTools Network for requests to googleadservices.com/pagead/conversion/XXXXXXXXX/ (conversion pings) and googleads.g.doubleclick.net/pagead/viewthroughconversion/ (remarketing). The presence of these beacons confirms the tags are firing and reveals the conversion ID.

Does the _gcl_aw cookie indicate Google Ads?

Yes. _gcl_aw is a first-party cookie Google Ads sets to store the click identifier (gclid) so a later conversion can be attributed to the originating ad click. Finding it is a strong sign the site uses Google Ads conversion tracking.

Can a site use Google Ads tracking without showing ads to me?

Absolutely. Conversion and remarketing tags are invisible measurement code; they do not display ads on the site itself. They simply record visits and conversions and feed audiences that the advertiser targets elsewhere across Google's network.

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