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Guide 79 · Consent · GA4 + Tag Manager

Consent mode basic: Google tags stay blocked until the visitor answers the banner

Checked 11 November 2026 · Verification: figures recomputed in Python 3, shown in the downloadable file · Steps traced to Google help and developer pages, opened 11 November 2026 · 7-minute read

In basic consent mode no Google tag loads and nothing is sent to Google until the visitor interacts with the consent banner. This guide sets that expectation before you build it.

Expected signal

After the trace, a visitor who has not answered the banner sends nothing to Google, and a visitor who grants consent loads the Google tag and sends full measurement.

Download the reference: the consent mode basic reference (JSON) (392 bytes, MD5 b08b1d61d5247328bfa0e2c26e1c62bf). It holds the worked example from this guide with every figure recomputed. The file was built for this guide and checked the same day; it was not exported from a live property.

What you need

  • A consent banner or consent management platform that can hold Google tags back.
  • Google tags installed through Tag Manager or the Google tag.
  • A written decision on which consent types your site asks for: analytics_storage and ad_storage at minimum.

The trace

  1. Read Google's definition first. In basic consent mode you prevent Google tags from loading until a user interacts with a consent banner. This setup transmits no data to Google before that interaction.
  2. Set the banner to block Google tags by default. Tags do not load on page open. They load only after the visitor grants consent, and then they send the default consent states followed by the updated states.
  3. Know what a refusal means in this mode. When the user does not consent, no data is transferred to Google at all, not even the consent status. Google tags are completely blocked from firing.
  4. Accept the modelling trade that follows. Conversion modelling in Ads is then based on a general model, not on your own site's data, because Google received nothing to model from.
  5. Check the worked example in the download. Out of 1,000 visitors, 412 grant, 388 deny and 200 do not answer. In basic mode the 388 who deny and the 200 who do not answer send nothing, so 588 of 1,000 visitors, 58.8%, produce no data at all. Only the 412 who grant are measured.
  6. Confirm the choice with the person who owns privacy for the site. Basic mode is the conservative choice, because nothing leaves the browser before consent. Record the decision and the date, so a later change of mode is traceable.

Dead ends

DEAD END — EXPECTING MODELLED DATA FROM BASIC MODE. There is nothing to model from when nothing was sent. If you need modelled conversions, basic mode cannot supply them.

DEAD END — THINKING CONSENT MODE IS A BANNER. Consent mode does not provide a banner or widget. It receives the choice from your banner and passes it to Google tags.

DEAD END — A TAG THAT LOADS ANYWAY. A tag without built-in consent checks can load even when consent is denied. In Tag Manager, add checks under Advanced, then Consent Settings, for any tag that lacks them.

End state

The worked example is stark: 588 of 1,000 visitors send nothing in basic mode, and only 412 are measured. That is the price of the conservative setting, and it is the number to quote when the mode is reviewed.

Sources

Checked 11 November 2026. The click paths above are the ones in Google's help and developer pages, opened 11 November 2026. No step in this guide was run inside a live Analytics property or a live Tag Manager container, because both need a Google sign-in and this site does not sign in as anyone. The figures on this page were recomputed in Python 3 and are shown in the downloadable file, which was checked the same day. Google moves menu items without warning; if a path on this page no longer matches, the linked help page is the current map.