Fingerprinting before consent

Why this matters

Fingerprinting-related APIs can create a tracking surface even when cookies are limited. If those signals are triggered before user choice, the issue is often harder to spot than cookie-based tracking.

How to verify manually

1. Identify which script executes canvas, WebGL, font, or device-probing APIs before consent.
2. Check whether the signal comes from analytics, fraud tooling, ad tech, or a custom script.
3. Confirm whether the script is essential or optional for baseline site functionality.

Typical root causes

• Fraud, attribution, or analytics vendors initialize immediately on page load.
• Custom anti-bot logic runs before the CMP decides.
• A vendor SDK bundles fingerprinting behavior you did not explicitly configure.

GTM fix

1. Move optional vendors that perform browser fingerprinting behind consent checks.
2. Review custom HTML tags and vendor templates for immediate initialization.
3. Separate strictly necessary fraud-prevention logic from optional analytics or advertising tooling.

WordPress fix

1. Review plugins for analytics, ads, AB testing, and anti-fraud features that inject scripts globally.
2. Disable optional optimization or attribution modules until consent is granted.
3. Retest after plugin updates because SDK behavior can change over time.

Generic fix

1. Defer non-essential SDK initialization until consent is granted.
2. For necessary risk controls, minimize scope and document why the behavior is essential.
3. Remove or replace vendors that cannot be configured to respect consent.

How to confirm the fix worked

• Confirm fingerprinting-sensitive APIs no longer run before consent.
• Re-test after Accept to ensure optional vendors still work when consent is granted.
• Run a fresh scan and compare the fingerprinting evidence before and after the fix.