Tracking and analytics
Tracking checker for GTM, GA4 and Consent Mode
Paste a page address to see which tag managers, analytics, ad pixels and consent tools appear in the page HTML, with their IDs. Duplicates and Consent Mode gaps are called out.
Runs on our edge server; we fetch the public page once and do not store it beyond a 10 minute cache.
Method
How it works
The checker reads the final HTML the server returns, after following redirects. It looks for container and property IDs and for the script hosts and calls each tag uses. Only the raw HTML is read, so nothing runs in the page.
Found items show their IDs. Not-found items mean the tag is absent from the raw HTML, which is not the same as absent from the live site. Use GTM Preview and your analytics realtime view to confirm what fires.
Consent Mode is read from the default call. The checker reports whether ad_storage, ad_user_data, ad_personalization and analytics_storage are set, and which consent banner the page loads.
FAQ
Questions people ask
What does "Found in page HTML" mean?
It means the tag ID or script appears in the HTML our server received for the page. It does not prove the tag fires for every visitor, because consent banners, GTM triggers and server-side setups change what runs. Confirm with GTM Preview and your analytics realtime view.
Why does a tag I know is installed not appear?
Tags that Google Tag Manager injects after the page loads, and tags a consent banner loads only after a choice, are not in the raw HTML. They are missing from this report even when they work. GTM Preview shows the full set of tags that fired.
What is Consent Mode v2?
Consent Mode lets Google tags adjust what they do based on consent signals. Version 2 adds ad_user_data and ad_personalization alongside ad_storage and analytics_storage. The default call sets those values before a visitor chooses. This checker reads the default call in the HTML and reports each key.
Why does the checker warn when gtag.js and GTM are both present?
Both can load the same GA4 property. If a GTM container also has a GA4 Configuration tag for the ID that gtag.js loads, each page view is sent twice. The checker cannot see inside GTM, so it asks you to confirm in GTM Preview.
What is a server-side tagging hint?
When GTM or gtag.js loads from a domain other than googletagmanager.com, such as a first-party subdomain, the site may use server-side tagging. The checker reports the host so you can confirm it belongs to your container.
Does a Universal Analytics (UA-) tag still work?
Standard Universal Analytics properties stopped processing new hits in 2023. A leftover UA tag adds page weight and makes audits harder. Remove it once GA4 data is confirmed in your reports.
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Next step
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