Basic consent mode blocks Google tags until the visitor answers the consent banner, so nothing is sent if they decline. Advanced consent mode loads tags immediately with consent denied by default and sends cookieless pings when visitors decline, which gives Google Ads a more detailed, advertiser-specific conversion model instead of a general one.
Both versions respect the visitor's choice. Google says that when visitors deny consent, consent-aware tags don't store cookies. The difference is what happens before the visitor answers the banner, and what Google receives after they say no.
How do they compare?
| Basic consent mode | Advanced consent mode | |
|---|---|---|
| When Google tags load | Only after the visitor interacts with the consent banner | As soon as the page opens |
| Default consent state | Not sent: no data goes out before consent, not even the default state | Denied, unless you set your own defaults |
| If the visitor declines | Nothing is sent | Consent state and cookieless pings are sent |
| If the visitor accepts | Tags load and measure normally | Cookies are written and all measurement data is sent |
| Google Ads conversion modeling | General model, less detailed | Advertiser-specific model, more detailed |
| GA4 behavioral modeling | Not eligible | Eligible if your property meets the thresholds |
What is in a cookieless ping?
When consent is denied in advanced mode, Google tags still send consent state pings for Google Ads and Floodlight, key event pings and Google Analytics pings. Google lists what they contain:
- Functional data: timestamp, user agent (web only) and referrer.
- Coarse data: whether the current or a prior page had ad-click information in the URL, the consent state, a random number generated on each page load, and which consent platform you use.
No cookies are stored. These pings are what feed the more detailed, advertiser-specific model in the table above.
Which one should you choose?
Start with how much traffic you have, because the modeling benefit of advanced mode only arrives above certain volumes:
- Google Ads conversion modeling needs 700 ad clicks over 7 days, per country and domain grouping.
- GA4 behavioral modeling needs the advanced implementation, at least 1,000 events per day with analytics storage denied for 7 days, and at least 1,000 daily users with it granted for 7 of the previous 28 days. Google adds that meeting these doesn't guarantee eligibility.
In practice: if your account clears those numbers, advanced mode is worth a conversation with whoever owns privacy and legal at your company, because it gives bidding a more detailed model. If your lawyer wants nothing to leave the browser before consent, basic mode is the answer, and you accept a less detailed model.
Either way, the setup starts with a banner. Google says that after you install a CMP partner banner, you can use either basic or advanced consent mode. I walk through both options in Google Tag Manager in my consent mode v2 guide. If you're still deciding whether you need any of this, read is consent mode mandatory first.
Sources
- Google Ads Help: About consent mode - https://support.google.com/google-ads/answer/10000067?hl=en
- Google for Developers: Consent mode overview - https://developers.google.com/tag-platform/security/concepts/consent-mode
- Google Ads Help: About consent mode modeling - https://support.google.com/google-ads/answer/10548233?hl=en
- Google Analytics Help: Behavioral modeling for consent mode (GA4) - https://support.google.com/analytics/answer/11161109?hl=en
- Google Ads Help: Set up consent mode - https://support.google.com/google-ads/answer/14009635