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Cookie Management

Cookie policy

When you visit a website published by a CNRS entity, information may be recorded in “cookie” files deposited in the browser of your terminal (computer, tablet or mobile phone). This page allows you to understand what a cookie is, what it is used for and how you can accept or refuse those that are not essential to the functioning and management of the site.

What is a cookie?

Cookies are text files with small pieces of data — like a username and password — that are used to identify your computer as you use a computer network. Specific cookies known as HTTP cookies are used to identify specific users and improve your web browsing experience.

Data stored in a cookie is created by the server upon your connection. This data is labeled with an ID unique to you and your computer.

When the cookie is exchanged between your computer and the network server, the server reads the ID and knows what information to specifically serve to you.

Cookies are managed by your internet browser and the user can read them by right-clicking on the web page and “Inspect Code”.

Only the sender of a cookie can modify the information contained in it. A cookie can be either a session cookie or a permanent (or persistent) cookie.

A session cookie persists only during the browsing session and is deleted when the browser is closed. A permanent cookie is installed for a specific period of time. This type of cookie remains in the terminal until it expires or until it is deleted from the computer via the browser settings or extensions.

The cookie does not identify you personally, but only the browser of your terminal. Some cookies require your prior consent before being installed on your terminal.

What are cookies used for?

Required cookies

These are cookies placed exclusively by the site editor. They are essential for the functioning of a website. These cookies cannot be deactivated or configured, otherwise you will no longer be able to access the site, the sites services and/or alter its display. They allow you to use the main features of the site and to secure your connection. The deposit of these cookies does not require your prior consent. Their lifespan generally does not exceed the duration of the session.

Functionality cookies

These cookies are necessary for the operation of the website. The deposit of these cookies does not require your prior consent. These cookies allow us to:

  • Establish anonymous statistics on the number of visitors and the use of the various elements of the site to enable the editor to administer and improve the site.
  • To adapt the presentation of the site to the display preferences of your terminal (language used, display resolution, operating system used, etc.) during your visits to the site, according to the hardware and software for viewing or reading that your terminal has.

The sites published by the CNRS entities use the Matomo hearing analysis tool, which complies with the RGPD specifications. The Matomo tool can deposit several cookies with a lifetime ranging from session time or a few tens of minutes to 11 months.

Functionality cookies deposited by the CNRS


  • Name: _pk_ses

Service provided: Traffic statistics (Matomo)

Purpose: This cookie temporarily stores the current session.

Duration: 30 minutes


  • Name: _pk_id

Service provided: Statistics of frequentation (Matomo)

Purpose: This cookie assigns a unique identifier to the user.

Duration: 11 months


  • Name: _pk_testcookie

Service provided: Statistics of frequentation (Matomo)

Purpose: Checks if the browser accepts cookies.

Duration: Session



Service provided: CSRF protection (cross-site request forgery)

Purpose: Prevents fraud, protects the user and the reliability of the data collected by Matomo.

Duration: Session

Third party cookies

Some sites may include computer applications from third parties that may deposit “social” and advertising, targeting and tracking cookies.

In particular, the services of:

  • Consent or refusal to deposit cookies by the Axeptio tool, published by the French company Agilitation, which has been chosen by the CNRS to manage cookies
  • Viewing of content by hosts such as YouTube, Dailymotion etc. for videos.
  • Sharing information on social networks that allow you to share the content of the site with other people or to let these other people know your consultation or your opinion concerning a content of our site.

The cookies placed by these third parties may remember the pages and websites you have visited and may collect personal data such as IP address and share it with third parties. These cookies allow advertising agencies to present you with targeted and personalized advertising. Their lifespan is variable, ranging from the time of a session or a few dozen minutes to several years.


The CNRS site you are visiting has no control over the process used by content hosts and social networks to collect information relating to your browsing, and associated with the personal data they hold.

It is possible for you to manage the deposit of these cookies. To view certain content offered by the CNRS, you must first accept cookies from these third parties.

How to manage the cookies deposited by this CNRS website?

Cookies whose sole purpose is not to enable or facilitate communication by electronic means or not strictly necessary for the provision of an online communication service at the express request of the user require the prior consent of the Internet user.

Tracers whose purpose is limited to measuring the anonymous audience of the site or application, to meet various needs necessary for the functioning and current administration operations of a website are not subject to consent.

To manage the cookies deposited by a CNRS site, you therefore have several possibilities that complement each other:

  • Accept or refuse unnecessary or non-functionality cookies with the Axeptio certified consent tool which is offered or being installed on most CNRS sites. On the sites concerned, a “Cookie management” widget button allows you to accept or refuse cookies requiring consent, in particular those from third-party companies. The widget provides information on the purposes of these cookies and a link to their privacy policy via a “?”
  • Exercise your choices with third party companies by consulting their privacy policy. There you will find the purposes of use, particularly advertising, and the browsing information that they may collect thanks to the application buttons available on the site consulted, and you will be able to set your user accounts to accept or refuse the cookies deposited by these companies.
  • Control cookies using your browser settings. Most of these cookies can be disabled by setting your browser to only accept cookies from the sites you visit (refuse “third party sites”, check the Do not track me box on most browsers) in your browser preferences. In “Private Browsing” mode, cookies will only disappear when you close the browser window on the site.


How to set up browsers?

In order to manage cookies as closely as possible to your wishes, we invite you to set your browser’s parameters taking into account the purpose of the cookies:

  • The web browser can be set to warn you before a cookie is set.
  • The browser can also be set to refuse all types of cookies or only third party cookies.
  • Any cookies already installed on the computer can be deleted.
  • Each browser must be set up separately to refuse cookies.


Disable/Delete Cookies on your browser

For Internet Explorer™:


For Safari™: 


For Safari™mobile:


For Chrome™:


For Firefox™:


For Opera™ :


For Microsoft Edge™:


Use blockers for cookies and other trackers via browser extensions such as:




Blocking mandatory or functional cookies may disrupt your browsing experience and restrict the services offered.

Managing advertising cookies from certain advertisers on two professional platforms and at Google:


Disable social network cookies


  • Twitter :


Setting up your smartphone

For iOS™:

For Android™:

Other browsers: For more information on how to manage cookies through other browsers, please consult your documentation or online help files.

You can also consult the CNIL website to learn how to set up your browser to control the deposit of cookies on your terminal.

CNRS Data Protection Officer

For any questions about the cookie management policy, contact the CNRS Data Protection Officer

Contact the DPO