What Is GCS? Decode Consent Mode Values (G100, G111 Explained)
Seeing a gcs=G100 or similar value and not sure what it means?
This is a Consent Mode signal — and if it's wrong, your Google Ads conversions may not be attributed correctly.
Decode your value below and check if your tracking setup is working properly.
Not sure if your consent signals are correct?
Run a free scan and detect issues across consent, tracking, and attribution.
Run Free Scan →Common scenarios
- GA4 shows conversions but Ads doesn't
- Consent banner implemented but tracking inconsistent
- Server-side tagging with unclear consent signals
If you're experiencing any of these, your consent signals (including gcs) may be incorrect or not updating after user action. Use the Consent Mode v2 check and default-denied snippet as a baseline, then debug GA4 vs Google Ads gaps.
Why this matters
If the gcs value does not update correctly after user consent:
- Google Ads may lose attribution
- Conversions may be underreported
- Campaign optimization may break
This is one of the most common causes of “GA4 works but Google Ads doesn’t.” Wrong signals often look technical (a single parameter), but the business impact is wasted spend and blind bidding.
Run a free scan to see whether updates, timing, and tags match real consent behavior — not just what the snippet looks like in the editor.
Then confirm conversion firing end-to-end with the conversion tracking test guide.
What is gcs?
gcs is a consent state signal carried on Google tags under Consent Mode. It should shift between default-denied and post-Accept values. Pair decoding above with live Consent Mode verification, copy-paste-ready default denied code, and — when Ads is silent — GA4 vs Google Ads troubleshooting.