No signup, nothing stored. Checking somebody else's site is fine: this only reads what every visitor's browser already downloads.
This checks the page your address serves to a normal visitor, the same way a browser would, and it opens any Google Tag Manager container it finds and reads inside it. Nothing is stored, no signup is asked for, and the answer is the same one you would get by opening the page source yourself with more patience than most people have.
A cookie banner is not Consent Mode
This is the misunderstanding that catches nearly everyone. A banner asks the visitor and stores the answer. Consent Mode is the separate step that passes that answer to Google's tags, as ad_storage, analytics_storage, ad_user_data and ad_personalization. A site can have a beautiful, fully compliant banner and send no consent signal at all, and from the outside the two are indistinguishable.
What v2 added, and why it was not optional
Version 2 added ad_user_data and ad_personalization on top of the original two parameters. Google made them a requirement for advertisers serving EEA and UK traffic in March 2024. The consequence of missing them is not a warning or a suspension, it is that remarketing lists stop refreshing and modelling stops, which looks like your campaigns slowly getting worse for reasons nobody can point at.
Basic and advanced, and why the choice matters
In basic mode, tags do not load at all until consent is given, so a visitor who ignores the banner is completely invisible. In advanced mode, tags load and send cookieless pings that carry no identifiers, which lets Google model the conversions it cannot observe. Advanced recovers substantially more reporting, which is why it is the usual recommendation, but it is a decision to take with whoever advises you on data protection rather than one to copy from a blog.
How to verify it properly
Open Chrome DevTools, go to the Console, and type dataLayer before touching the banner. You should see a consent default entry with the four parameters set to denied. Accept the banner, look again, and you should see a consent update flipping them to granted. If the default entry is missing, the signal is not being sent regardless of what your consent platform's dashboard reports.
Common questions
Do I need Consent Mode if my customers are all in the United States?
Google's requirement applies to EEA and UK traffic. If genuinely none of your visitors are there, it does not apply to you. Check your Analytics by country before concluding that, because a surprising number of local businesses have a small European tail and the requirement follows the visitor, not the business.
My consent platform says it is enabled. Why does this say no?
Most often because the platform is loading after Google's tags, so the consent default arrives too late to matter. Order is the whole thing here: the default has to be set before any Google tag loads. The dataLayer check above shows which happened.
Will Consent Mode reduce my reported conversions?
In basic mode, usually yes, because tags stop firing for anyone who has not consented. In advanced mode, reporting typically recovers a good part of that through modelling. Either way the conversions were already being lost. What changes is whether you can see an estimate of them.
Is this a legal compliance check?
No, and it should not be treated as one. It reports one technical fact: whether a consent signal is being sent to Google's tags. Whether your overall setup meets GDPR or any other law is a question for someone qualified to answer it.