Navigation fingerprinting: tracking anonymous users without cookies

One of the most frequent questions we get at FLYDE is: can we identify anonymous users on our website through fingerprinting? And do we need their consent to do it?

It's an important question. As data strategies become more sophisticated, marketing teams are looking for ways to understand user behavior from the most top-of-funnel stage through to conversion. On many platforms, anonymous website visits stay isolated from the rest of the customer journey.

Imagine an anonymous user clicks on a campaign, visits several pages on your site, and returns more than once. All of that part of the customer journey, before the user identifies themselves, is lost. This is where navigation fingerprinting comes in.

From third-party cookies to fingerprinting

For years, digital marketing has relied on third-party cookies to track user browsing. These cookies have been key for retargeting, personalization, and attribution. But browser updates and privacy regulations have changed the rules.

• Safari and Firefox began blocking third-party cookies by default.
• Google Chrome has been in the process of phasing them out.
• Privacy regulations have tightened consent requirements.
• Users are better informed and more selective about how their data is tracked.

With the end of third-party cookies, navigation fingerprinting has gained prominence as an alternative. As with cookies, its use for marketing purposes is subject to privacy regulation.

What is navigation fingerprinting?

Navigation fingerprinting, also known as browser fingerprinting or device fingerprinting, is a technique that identifies a device based on technical characteristics, without needing to install a cookie.

When someone visits a website, their browser reveals a series of attributes, such as:

• Browser version and operating system.
• Language, time zone, and screen resolution.
• Installed plugins or fonts.
• Device input type (touch or keyboard, for example).

Combined, these signals form a kind of unique digital fingerprint. With the right configuration, this fingerprint can be used to recognize a returning visitor who browses the site anonymously.

Why does it matter for marketing?

In theory, fingerprinting allows marketing teams to:

• Track anonymous users across multiple sessions.
• Activate personalized experiences from the earliest stages.
• Detect fraud or suspicious behavior.
• Link anonymized behavior to the user's profile once they identify themselves.

It's a powerful tool. For example, platforms like Meta or Google only offer aggregated information about anonymous users. But with FLYDE's browser tracking system, you can link an advertising campaign to a specific user if they arrive at your site through a tagged UTM and later identify themselves (for example, by leaving their email) and give their consent. This lets you connect the user's anonymous behavior with their identified data, gaining a complete view of their journey from the first click to conversion.

How FLYDE guarantees privacy and performance

At FLYDE we believe privacy and performance can go hand in hand. We embrace fingerprinting and advanced browser-tracking techniques, always within a responsible, user-centric framework.

Privacy is guaranteed at two levels:

• Mandatory cookie consent: if you install FLYDE's tracking script through Google Tag Manager, tracking only activates once the user accepts your site's cookie policy.
• Legal basis for identification: a person is only identified when they register or leave their email. At that moment, they have accepted your legal terms for data processing.

This lets you activate valuable data while always respecting user privacy and without putting compliance at risk.

From navigation to insight

Once the user has given their consent, you can activate that data in meaningful ways:

• Segment audiences based on website behavior (for example, pages visited, visit duration).
• Enrich campaigns with cross-channel tracking (for example, email clicks, visits from ads).
• Score leads in real time with the Lead2Customer algorithm, which assigns a conversion probability from 0 to 10 based on browsing patterns and level of interaction.

You can activate personalized flows, build predictive segments, and prioritize follow-ups with the confidence of having a complete view of the customer journey.

How FLYDE can help

Fingerprinting can help you better understand user behavior, even in the earliest phases of the customer journey. A Customer Data Platform (CDP) like FLYDE lets you make the most of every interaction, whether tracking anonymous sessions, running predictive models, or building smarter segments.

Contact us to schedule a meeting and see how it could apply to your team.