•   Safari Browser      

In the Safari app  on your Mac, choose Safari > Preferences, click Privacy, then do one of the following:

To always block cookies: Select “Block all cookies”.

Websites, third parties and advertisers cannot store cookies and other data on your Mac. This may prevent some websites from working properly.

To delete stored data and cookies: Click Manage Website Data, select one or more websites, then click Delete or Clear All.

Deleting the data may reduce activity tracking, but may also sign you out of websites or change the behavior of websites.

To see which websites store cookies or data: Click Manage website data.

Ask websites not to track your activities: Some websites track your browsing activities when they present content to you, allowing them to personalize your content. You can configure Safari to instruct sites and their third-party content providers (including advertisers) not to track your activities.

When this option is enabled, each time Safari retrieves content from a website, it asks it not to track your activities, but be aware that each site chooses whether or not to honor this request.

• Google Chrome

In Chrome, go to the Privacy and security section of the settings (chrome://settings/privacy). Here, a Content setting option is accessible. It contains an element relating to cookies. You can directly reach    

this page via the URL chrome://settings/content/cookies.

Several choices are then available to you: completely disable access to cookies, keep them only for the duration of the session (they will then be deleted as soon as the browser is closed) or block only third-party cookies.

For each choice you can also opt for a list of exceptions site by site:

A tool allows you to see the list of all cookies in order to analyze or delete them. This area is also accessible by clicking to the left of a site's URL in the address bar. A bubble will then appear, detailing the number of    

cookies in use.

This information takes the form of a clickable link that will give you access to a list allowing you to view, block or delete items as you see fit.

• Mozilla Firefox

On Firefox, while one might expect a simple and comprehensive solution, this is not really the case. You have to go to the Privacy and security section of the Options (about:preferences#privacy) where almost no settings concerning the management of cookies are displayed. By default, you can indeed only delete specific cookies.

For retention options, first set the Retention rules setting to Use custom settings for history. We can then accept or not cookies in general or only third-party cookies. A tool for displaying cookies and another for managing exceptions are offered.

Note two interesting points. First of all, it is possible to choose not to retain cookies once the session has ended. But above all, an option specific to third-party cookies is available: From the sites visited. It consists in authorizing third-party cookies as long as it is a site on which you have already visited which tries to deposit them. A way to solve the problems that can possibly arise from a complete deactivation.

To see the cookies of a particular site from a browsing page, the easiest way is to right-click and then select Information on the page. In the Security tab, a View Cookies button will be available. You can also opt for the Storage Inspector (SHIFT+F9).  

Finally, note that Firefox offers other options regarding privacy such as protection against tracking, first-party isolation or contexts.

• Opera and Vivaldi

Both browsers offer identical operation for managing cookies. In the settings, a section relating to privacy contains a dedicated area. You can block or accept all cookies or only third-party cookies. A tool allows you to view them directly.

Opera also offers exception handling, which is not yet the case with Vivaldi.  

Microsoft Edge

Under Edge, it's a little more limited and just as convoluted. You have to go to the browser settings and then to the advanced settings section. At the very bottom, an element relating to cookies is offered with three options: block all, allow all or only block third-party cookies.

No site-by-site settings are offered, nor is a tool to view or manage the cookies available. Only solution: opt for the development tools (F12), which offer what you need in its Debugger section. An alternative found in all other browsers.

• Delete cookies in Firefox

Launch the browser and press Alt + O simultaneously.

Select Options from the menu,  

Go to the Privacy tab, then click on the link delete specific cookies.

The window that opens allows you to delete the cookies of a particular website or all the cookies present on your system.

• Delete cookies in Internet Explorer

Launch the browser and press Alt + U simultaneously.

Select Internet Options.

In the General tab go to the browsing history level and click on Delete…

Check the Cookies and website data box and press the Delete button again

 

• For all other browsers, please consult their settings by referring to the help section if necessary.