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How to check if a website uses Google Analytics 4

By SearchWebCode · Updated November 7, 2026 · Detection · 2 min read

A tag in HTML and a collection request in the browser are different observations. The first shows what the page references; the second shows that a request was made during your visit. Start with source, then use the Network panel if you need to check activity.

Look for a direct GA4 tag

Open View Page Source and find gtag/js?id=G- or gtag('config'. A direct installation can contain:

<script async src="https://www.googletagmanager.com/gtag/js?id=G-ABCDE12345"></script>
gtag('config', 'G-ABCDE12345');

The ID is illustrative. An AW- Ads reference or a GTM- container alone does not establish GA4 collection. A GT- Google tag can have connected destinations, so inspect its configuration or requests. The Analytics ID reference explains the formats.

Inspect browser collection requests

1. Open DevTools → Network before loading the page. Keep the request log if you need to follow navigation.
2. Filter for collect or g/collect.
3. Inspect the request URL and payload for the destination measurement ID, commonly in a tid parameter.
4. Record the page, time and consent state with what you observed.

Consent settings, content blockers and server-side tagging can change what appears. A collection endpoint may use a first-party hostname. An HTTP success response is evidence of the request, not confirmation that an event appears in the account's reports. Google's tag troubleshooting documentation covers checks on sites you administer.

Check a Tag Manager installation

If source contains only a GTM- ID, load the page and inspect the requests it makes. A container can deploy GA4, Ads, other vendors or no active Analytics tag. Tag Assistant can help inspect the Google tags observed in a browser session.

Finding an ID in a container script shows that the value is present in its configuration. It does not by itself show that the relevant tag was triggered on the page.

Find other websites with the same tag

Search an observed ID exactly, as in "G-ABCDE12345", then follow the shared Analytics ID lookup. For direct-loader references across the index, search "gtag/js?id=G-". The GA4 technology sample reports 9,897,422 estimated matches for that string.

That source count misses tags loaded through containers or other paths. It also cannot tell whether the tag sent events. To check a supplied list of domains, compare an exported footprint list with your list, then verify the important sites in a browser. SearchWebCode's site: filter selects a domain suffix, not one hostname.

Source counts checked 2026-10-14. They describe stored homepages, not live installations. How the counts are measured.

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