Fireshift / Features / Two GA4 properties
Two GA4 properties on one site: the check
We collect every GA4 measurement ID (G-…) in the page HTML and in the GTM containers the site loads, and flag the site when there are two or more. On 5 Nov 2026, 35 of 162 B2B SaaS sites that load GA4 (21.6%) loaded two or more: 28 loaded two, 6 loaded three, one loaded five. Our 4 Nov study found 17.5% of 223 GA4 sites. Two properties can be on purpose; check that only one feeds Google Ads.
5 Nov: static rescan of 285 B2B SaaS domains (values-2026-11-05.json). 4 Nov: study of 449 sites. Both are hand-picked samples, not random.
What we detect
Every distinct G- ID found in the HTML of the homepage, /pricing, /signup and /demo, plus the GA4 IDs referenced by the GTM containers those pages load. Two or more distinct IDs is a finding. Score: −7. We list the IDs (masked in reports we publish) so you can match them to your properties.
Where the second property comes from
Of the 35 sites with two or more GA4 properties on 5 Nov 2026:
| Source of the GA4 IDs | Sites |
|---|---|
| All of them configured in one GTM container | 27 |
| Spread over two or more GTM containers | 3 |
| One in the page HTML (hardcoded gtag), another from GTM | 5 |
GTM-•••• Google tag G-•••• (all pages)
GTM-•••• Google tag G-•••• (all pages) second GA4 property, same container
So the usual case isn't a forgotten snippet. It's two Google tags inside the same container, which is easy to check in GTM: filter Tags on "Google tag" and read the measurement IDs.
Why it matters
- Double counting in Ads imports. If key events from both properties are imported into Google Ads, the same signup can arrive twice.
- Two versions of the truth. Teams report from different properties and the numbers don't match.
- Two places to fix consent. Both properties have to respect the banner.
When it is fine: a roll-up property that collects several sites, or a separate property for an agency or a product team, on purpose and documented.
How to fix it
- List the IDs and find which GA4 property each belongs to (Admin, Data streams).
- Decide which one is the source of truth for marketing and Ads imports.
- Remove the extra tag, or keep it and make sure only one property's key events are imported into Google Ads.
- Search the page source for
gtag(andG-too. On 5 of the 35 sites, one ID was hardcoded and never shows in GTM.
What we can't see
- Whether both properties are linked to Google Ads, and which key events are imported.
- GA4 tags that only load after consent or from a server-side container.
FAQ
Is it bad to have two GA4 properties?
Not by itself. It's a problem when both feed Google Ads or nobody knows which one is the source of truth.
Where do I find the second property?
Usually in GTM: on 27 of 35 sites both IDs were Google tags in the same container. On 5, one was hardcoded in the page; search the source for gtag( and G-.
Does this check need access to GA4?
No. Measurement IDs are in the public page and container. Which property is linked to Ads needs access.
Check your own site, free.
Fireshift reads what your site tells Google Ads, GA4 and Meta from the outside. No install, no account access.
Scan my site