Documentation

Google load mode

Choose when Google loads

The gtag and googleTagManager helpers take a loadMode option. It decides whether the page contacts Google before the helper's category is allowed:

`loadMode`	Until the category is allowed	Use it when
`'always'` (default)	c15t loads Google's script, sends Consent Mode `default` with the current permissions, then sends `update` as they change. Google receives requests with the optional consent types denied.	You want Consent Mode signals from visitors who have not allowed the category.
`'after-consent'`	c15t sends no request to Google.	Your site must make no request to Google before opt-in. You give up Consent Mode's cookieless pings and conversion modeling for visitors who haven't allowed the category.

With 'after-consent', gtag waits for its category, and googleTagManager waits for measurement or marketing because a container usually holds both kinds of tag. Pass category to googleTagManager to change that, for example category: 'measurement' for an analytics-only container. Until the helper loads, window.gtag doesn't exist, and neither does window.dataLayer unless you seeded it, so event calls written as window.gtag?.(...) do nothing.

'after-consent' waits for the category to be allowed, not for a recorded choice. Under an opt-in policy, that happens when the visitor allows it. Under an opt-out or none policy, optional categories are allowed before a choice, so the helper loads on the first page.

In either mode, the container runs every tag in it once it starts. Google tags inside follow Consent Mode, but Custom HTML tags and third-party pixels fire on their own triggers. With the default category, a visitor who allowed only measurement starts the container, and a marketing pixel in it loads too. With 'always', both load before any choice. Add a consent check to each of those tags in GTM, or move the vendor out of the container to its own c15t helper. See configure consent inside the container.

Set it on each Google helper in your scripts array:

gtag({
	id: 'G-XXXXXXXXXX',
	category: 'measurement',
	loadMode: 'after-consent',
}),
googleTagManager({ id: 'GTM-XXXXXXX', loadMode: 'after-consent' }),

The Google Tag and Google Tag Manager guides list what each mode sends and how to check it in DevTools.