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Tag Health Checker
See which tracking tags your page loads, in seconds. Free, no signup.
Method
How it works
Paste a public page URL. The checker fetches that page on a server, reads the HTML, and then fetches up to two public Google Tag Manager container scripts it finds. Container JS is public; it is the same file a browser downloads.
There is no headless browser in this version. Tags that only appear after JavaScript runs, after a consent choice, or after a click are invisible unless they are already in the HTML or the container. The result list says what was found, not whether a conversion works.
Nothing is stored. The URL you paste and the findings are not kept after the result is returned.
The reads
Fourteen checks, each tied to a vendor doc.
Every row in a result links to the public documentation it is based on. None of these is a score.
- 01
Google Tag Manager present
Looks for googletagmanager.com/gtm.js?id=GTM- in the HTML, or GTM- IDs in the inline snippet.
Google Tag Manager for web - 02
Multiple GTM containers
Flags more than one distinct GTM- ID. Two containers can double-fire tags.
Google Tag Manager for web - 03
GA4 present
Looks for gtag/js?id=G- in the HTML, or G- IDs inside a fetched GTM container.
Google Tag Manager for web - 04
Same GA4 ID loaded twice
The same G- ID hardcoded in the HTML and inside GTM, or two gtag configs. Double-counted page views and events are the risk.
Google Tag Manager for web - 05
Google Ads tag present
Looks for AW- IDs in the HTML or the container. Presence is not proof that conversions fire.
Google Ads conversion tracking - 06
Meta Pixel present
Looks for connect.facebook.net fbevents.js and fbq init with a pixel ID. More than one ID is flagged.
Meta Pixel - 07
- 08
LinkedIn Insight Tag present
Looks for snap.licdn.com insight.min.js and _linkedin_partner_id.
LinkedIn Insight Tag - 09
- 10
Consent mode default
Looks for gtag consent default in the HTML before tag scripts, or consent settings visible in the container.
Google consent mode - 11
Consent banner (CMP) script
Recognizes Cookiebot, OneTrust, Usercentrics, CookieYes, and Termly script hosts when they appear in the HTML.
Google consent mode - 12
Tag order
Compares the position of a consent default with the first tag script in the HTML. Tags loading first is worth a look.
Google consent mode - 13
First-party / server-side signals
Looks for GTM or gtag loaded from the site’s own domain, and for server_container_url or transport_url in the config.
Server-side Tag Manager - 14
Tags in noscript only / broken snippet
A GTM noscript iframe without the script, or the script without the iframe, may mean a half-installed snippet.
Google Tag Manager for web
Worked example
A real run against this site
On 8 October 2026 the checker fetched https://mathermediasolutions.com and the public container for GTM-WKQJKGH6. These are the findings from that scan, not a grade.
Google Tag Manager present
GTM-WKQJKGH6 in the page HTML.
Found
Multiple GTM containers
One GTM container ID is referenced.
Not found
GA4 present
G-KL0GWKDQRP in the GTM container, not hardcoded in the HTML.
Found
Same GA4 ID loaded twice
The measurement ID appeared in the container only.
Not found
Google Ads tag present
No AW- ID in the HTML or the public container JS.
Not found
Meta Pixel present
No fbevents.js or fbq init in the HTML.
Not found
TikTok Pixel present
No TikTok pixel script in the HTML.
Not found
LinkedIn Insight Tag present
No Insight Tag script in the HTML.
Not found
Microsoft UET present
No UET script in the HTML.
Not found
Consent mode default
A gtag consent default is in the page HTML before the GTM loader.
Found
Consent banner (CMP) script
None recognized among the known CMP hosts.
Not found
Tag order
The consent default appears before the first tag script.
Found
First-party / server-side signals
GTM loads from googletagmanager.com. No server container URL was set in the config.
Not found
Tags in noscript only / broken snippet
The GTM script and noscript iframe are both present.
Not found
Scan dated 8 October 2026
Limits
Questions
Common questions
Is the tag checker free?
Yes. No signup, no email, no account.
Do you store the URLs I check?
No. The checker fetches the page, returns the result, and keeps neither the URL nor the findings.
Why does it say a tag is missing when I know it is there?
A page scan reads HTML and public GTM container scripts. Tags that load after consent, after a click, or from a script this tool cannot read will not show up.
Can it tell me if my conversions work?
No. It shows which tags load. Testing whether a conversion fires when someone books, buys, or submits a form needs the full journey.
What is consent mode and why does it matter?
Consent mode is Google’s way for tags to change behavior based on a visitor’s cookie choice. If a default is not in the HTML, it may still be set by your consent banner or inside GTM. Check with Tag Assistant. Google’s guide: https://developers.google.com/tag-platform/security/guides/consent
What does a first-party or server-side setup mean here?
It means GTM or gtag is loaded from the site’s own domain, or the config names a server container URL. That can mean more control over delivery. It does not prove the setup works. Google’s server-side Tag Manager docs: https://developers.google.com/tag-platform/tag-manager/server-side