Why You Should Verify in the Browser

A consent banner that looks right is not proof that your tags behave correctly. Consent Mode problems are silent: pages load, ads show, and reports fill up, yet the signals sent to Google may be wrong. The browser’s developer tools let you check what is really happening, in a few minutes, with no extra software.

Step 1: Open the Network Tab Cleanly

1. Open the page in a private window so no earlier choice is stored.
2. Open DevTools and go to the Network tab.
3. Tick Preserve log so requests survive navigation.
4. Reload the page and do not touch the banner yet.

Step 2: Find the Consent State in Requests

Google tags add a gcs parameter to their requests. You can filter the network list by collect or by google and open any hit to read its query string. The value looks like G100 or G111.

• G100 — both advertising storage and analytics storage are denied.
• G111 — both are granted.
• G101 and G110 — one granted and one denied.

Reading the characters from left to right after the G1: the first digit is the advertising storage state and the second is the analytics storage state, where 1 means granted and 0 means denied. Newer implementations also send a gcd parameter with a longer encoded state that includes the additional Consent Mode v2 signals.

Step 3: What You Should See Before Any Choice

In a region where consent is required, the first requests, sent before the visitor interacts, should show the denied state. If you already see G111 before the visitor clicked anything, your default is wrong, or the tag fired before the default was set.

Step 4: What You Should See After Accepting

Click accept, then watch new requests. The state should change to granted and the tags should proceed. If the banner says accepted but requests still carry the denied state, the update call is not reaching Google tags, or it runs too late.

Step 5: Inspect the Data Layer

In the Console, type dataLayer and expand the entries. You are looking for two things in order:

1. A consent entry with the default command, listing every signal as denied for regions that require consent.
2. A later consent entry with the update command, after the user chooses.

The Consent Mode v2 signals are ad_storage, analytics_storage, ad_user_data, and ad_personalization. If the last two are missing, you have a v1-style setup.

The Most Common Mistakes

• Default set too late. The default command must run before the Google tag or Tag Manager container loads.
• Update never sent. The banner stores a choice but never calls the update command.
• Only two signals. The v2 signals for user data and personalization are missing.
• Wrong region logic. Visitors from a region that requires consent are treated as granted by default.
• Blocked by an extension. A privacy extension in your own browser hides requests; test with extensions off.
• Cached choice. You tested in a normal window that already stored a previous choice.

Step 6: Check the Tag Manager Preview Mode

If you use Google Tag Manager, Preview mode shows the consent state for each event on the page, and which tags fired or were blocked. Compare it with what you saw in the network tab: both views should agree.

Make It a Routine

Run this five-minute check after every banner change, container publish, or site release. Write down the expected gcs value for four cases: first visit, after accept, after reject, and after changing the choice later. Anything that does not match is a bug to fix before your reports do the telling.

Where FlexyConsent Fits

FlexyConsent is a Google-certified CMP (CMP ID 317) that supports Google Consent Mode v2, sending the default and update signals for you. You should still run this browser check on your own pages, because tag order and container settings are specific to your site.

Key Takeaways

• Test in a private window with the network log preserved.
• Read the gcs value: G100 is denied, G111 is granted.
• The denied default must be visible before the visitor chooses.
• The update must change the state right after the choice.
• Confirm all four Consent Mode v2 signals appear in the data layer.