Cookie Report

Notice: This service is currently experimental. It should not be considered production-ready.

Capture reports of cookies being set by third-party scripts.

A plethora of different third-party and first-party javascript now commonly runs on most websites. Each of these scripts having their own motivations for persisting values in cookies. The cumulative effect of these cookies all being set on the same domain can have deleterious effects. The size of the cookies build up over time and can result in bloated HTTP request headers.

With ad-networks and tag managers often loading scripts indirectly from any number of other sources it can be difficult get a clear view of what scripts are responsible for setting what cookies, and consequently make decisions about how to control these cookies.

This is an experimental solution to getting a clearer view of what scripts are setting cookies. It may also provide a potential mechanism for proactively mitigating the problem of bloated use of cookies.

How it works

Javascript patches the document.cookie property used by other scripts to set cookies. It then intercepts assignments of cookies to gathers a reports of the size, name and the javascript file that was responsible for setting the cookie. These reports are sent using the sendBeacon API when the user navigates away from the page. The reports can then be collected in a central location and reviewed to determine what action should be taken to address the scripts that are responsible for setting unwanted cookies.

Installation and Usage

To install you can include the client script as part of your page so it runs before cookies are set by other scripts.

Install the NPM package

npm install --save @radical-research/cookie-report

Setup the client script

// Reference the client script - This defines the cookieReport function in global scope
require("@radical-research/cookie-report");

// Start capturing cookies
cookieReport();