__cfduid Cookie Explained in Detail (What to Know)


Cookies are not only used to collect our information. Many cookies exist to protect consumers and businesses. The _cfduid cookie is used for that exact purpose.

The _cfduid cookie is utilized by sites as a traffic controller. With the ID the _cfduid cookie provides, your site can successfully identify bots or unsafe traffic and block their entry. You have come to the right place to learn more about what the _cfduid cookie does and more.

This article will cover the _cfduid cookie’s indispensable security function, what it means for your business, and how long it lasts.

Let’s get started.

What is the _cfduid Cookie?

The _cfduid cookie is inserted by Cloudflare and is used as a barrier and checkpoint for traffic to your site. The _cfduid cookie’s primary function is to identify safe and trusted traffic to your site.

Typically, this cookie is used as a defense measure to prevent bots and other harmful entities from entering your website. The _cfduid cookie acts as a gate, picking out the good traffic from the bad, providing a much-needed layer of security for your site.

Without it, your site could be exposed to bots that can disrupt function or lead to targeted attacks on your site’s users.

When Does the _cfduid Cookie Expire?

The _cfduid cookie lasts 30 days on a user’s browser and will serve as the identifier of bad traffic during that time. After this cookie expires, it will likely be replaced and continue to serve as a needed defense against bots and other harmful traffic.

You can rest easy knowing the _cfduid cookie does not collect any personal information and does not interfere with the browser in any malicious way.


The _cfduid cookie works behind the scenes to identify safe traffic to your site. Cookies that provide this layer of defense are critical for your business to maintain adequate security and function on your site.

The _cfduid cookie does not go beyond its specific security role and does not collect personal information from users. Your business can’t overlook the importance of maintaining safe traffic for your site.

Get in touch with us today for a free consultation to find out if you are compliant with relevant regulations.