Suziwan

Suziwan Referrer Log is a simple yet powerful analytics tool developed in Nice, France, with privacy in mind. Unlike heavy third-party services, this plugin stores visitor source data locally on your server, giving you full ownership of your data.
It is specifically designed to track: 
* External Referrers: See which websites are sending traffic to your site. 
* Full UTM Tracking: Log source, medium, campaign, term, and content for your marketing campaigns. 
* Visitor Metadata: Capture landing URLs, browser languages, and user agents. 
* Data Management: Includes a settings page to easily clear all logs or purge old data (e.g., keep only the last 30 days) to keep your database lean.
Privacy First: 
To comply with global privacy standards like GDPR, this plugin automatically anonymizes IP addresses by masking the last octet before saving them to the database. No personally identifiable information (PII) is stored.

Suziwan Referrer Log

A lightweight, privacy-friendly way to log referrers, UTM parameters, and visitor metadata directly in your WordPress database.

averageradical

Non-technical summary: Track incoming referrer and write it to any hidden form field with the identifier “referrer” (this can be created in Contact Form 7, for example; see below). Also if the WordPress site redirects from HTTP to HTTPS, this plugin also overrides the redirect to add the referrer to the https URL.
Technical details: This plugin runs client-side JavaScript in every page in HEAD and if there isn’t a session cookie with the name “referrer”, then it writes a session cookie with the name “referrer” and the value of either document.referrer, or if that’s empty, the URL-encoded value of window.location.href. There is another client-side JavaScript in every page before which writes the value of the “referrer” cookie to any INPUT with the ID “referrer”, if it exists.
When integrating with Contact Form 7, add a hidden input field such as the following:
<pre><code>[hidden referrer id:referrer]
</code></pre>
And then add to the Mail’s Message Body:
<pre><code>Referrer: [referrer]
</code></pre>
If you’re just integrating this with HTML, just add this to any form:
<pre><code><input type="hidden" id="referrer" name="referrer" />
</code></pre>

track-incoming-referrer

Track incoming referrer and write it to any hidden form field with the identifier "referrer".

Suziwan Referrer Log vs track-incoming-referrer