Cookie banner: Definition, issues, and explanations

A cookie banner is a message or window that appears on a website to inform users that the site uses cookies. These cookies are small files stored on the visitor's computer or mobile device in order to collect browsing data or personalize their experience.

The main purpose of this banner is to ensure transparency for Internet users regarding the use of their data, in accordance with the legal framework in force, in particular the General Data Protection Regulation (GDPR) in Europe.

It is often positioned at the top or bottom of the page and frequently asks for the user's consent before placing certain types of cookies, particularly those that are not strictly necessary for the website to function.

The use of a cookie banner has become a legal requirement for most websites that collect personal data via cookies. This requirement aims to protect users' privacy and give them clear control over their data.

The cookie banner also helps build trust with visitors. By explicitly informing them about the types of cookies used and requesting their consent, the website demonstrates its compliance with regulations and ethical standards.

Furthermore, by complying with legal requirements, the site protects itself against potential penalties that may be imposed by supervisory authorities, such as the CNIL in France, which can be costly and damage the company's reputation.

When a user visits a website, the cookie banner automatically appears to inform them about the use of cookies. This banner usually offers several options, including accepting all cookies, refusing certain cookies, or managing preferences.

Visitors can choose to consent fully, partially, or refuse the use of non-essential cookies. This choice is then stored via a specific cookie so that the banner no longer appears on each visit.

In practical terms, the website must differentiate between cookies that are necessary for the strict functioning of the website (such as maintaining the session) and cookies used for tracking or advertising, which require explicit consent.

The main advantage of the cookie banner is that it ensures transparency and compliance with regulations, which strengthens users' trust in the website.

It also gives visitors greater control over their personal data, which is a very positive point in terms of user experience and privacy.

However, cookie banners can sometimes hinder the usability of a website by disrupting navigation, especially if their design is intrusive or poorly thought out. They can also lead to a decrease in cookie acceptance rates, which can limit data analysis capabilities for website optimization or advertising campaigns.

A common example is e-commerce sites that use cookies to personalize product recommendations. The cookie banner informs the user and allows them to accept or refuse these cookies.

News sites also often include a cookie banner to manage advertising tracking cookies in order to monetize their audience while complying with regulations.

In an institutional or banking setting, the cookie banner is used to ensure that users' sensitive data is not collected without consent, thereby ensuring enhanced compliance and better data security.

• CNIL - Cookies and trackers: what does the law say?
• Official website of the European Commission on data protection
• MDN - Documentation on HTTP cookies
• Osano Cookie Consent - Consent management tool