Regularly deleting cookie files reduces the risk of your personal data being leaked and used without authorization. In addition, deleting cookies can free up hard. Alles zu Cookies und Ihren Einstellungen. Nachfolgend erläutern wir zu welchen Zwecken wir Cookies sowie ähnliche Technologien auf unseren Websites. Persistent-Cookies bleiben auf Ihrem Computer gespeichert, je nachdem welche Lebensdauer für den Cookie festgelegt wurde. Erst nach Ablauf einer.
Cookie filesPersistent-Cookies bleiben auf Ihrem Computer gespeichert, je nachdem welche Lebensdauer für den Cookie festgelegt wurde. Erst nach Ablauf einer. Alles zu Cookies und Ihren Einstellungen. Nachfolgend erläutern wir zu welchen Zwecken wir Cookies sowie ähnliche Technologien auf unseren Websites. Cookies bieten Ihnen die Möglichkeit, direkt aus einer HTML-Datei heraus Daten auf dem Rechner des Anwenders zu speichern und beim.
For example, if the preferences of a user are encoded in the query string of a URL and the user sends this URL to another user by e-mail , those preferences will be used for that other user as well.
Moreover, if the same user accesses the same page multiple times from different sources, there is no guarantee that the same query string will be used each time.
For example, if a user visits a page by coming from a page internal to the site the first time, and then visits the same page by coming from an external search engine the second time, the query strings would likely be different.
If cookies were used in this situation, the cookies would be the same. Other drawbacks of query strings are related to security.
Storing data that identifies a session in a query string enables session fixation attacks, referer logging attacks and other security exploits. Transferring session identifiers as HTTP cookies is more secure.
Another form of session tracking is to use web forms with hidden fields. This technique is very similar to using URL query strings to hold the information and has many of the same advantages and drawbacks.
This approach presents two advantages from the point of view of the tracker. First, having the tracking information placed in the HTTP request body rather than in the URL means it will not be noticed by the average user.
Second, the session information is not copied when the user copies the URL to bookmark the page or send it via email, for example.
This data can be used instead of session cookies and is also cross-domain. The downside is that every separate window or tab will initially have an empty window.
Furthermore, the property can be used for tracking visitors across different websites, making it of concern for Internet privacy. In some respects, this can be more secure than cookies due to the fact that its contents are not automatically sent to the server on every request like cookies are, so it is not vulnerable to network cookie sniffing attacks.
However, if special measures are not taken to protect the data, it is vulnerable to other attacks because the data is available across different websites opened in the same window or tab.
Apple uses a tracking technique called "identifier for advertisers" IDFA. This technique assigns a unique identifier to every user who buys an Apple iOS device such as an iPhone or iPad.
This identifier is then used by Apple's advertising network, iAd, to determine the ads that individuals are viewing and responding to.
Because ETags are cached by the browser, and returned with subsequent requests for the same resource, a tracking server can simply repeat any ETag received from the browser to ensure an assigned ETag persists indefinitely in a similar way to persistent cookies.
Additional caching headers can also enhance the preservation of ETag data. ETags can be flushed in some browsers by clearing the browser cache.
Internet Explorer supports persistent information  in the browser's history, in the browser's favorites, in an XML store "user data" , or directly within a web page saved to disk.
Some web browser plugins include persistence mechanisms as well. The browser cache can also be used to store information that can be used to track individual users.
This technique takes advantage of the fact that the web browser will use resources stored within the cache instead of downloading them from the website when it determines that the cache already has the most up-to-date version of the resource.
After the user's initial visit, every time the user accesses the page, this file will be loaded from the cache instead of downloaded from the server.
Thus, its content will never change. A browser fingerprint is information collected about a browser's configuration, such as version number, screen resolution, and operating system, for the purpose of identification.
Fingerprints can be used to fully or partially identify individual users or devices even when cookies are turned off.
Basic web browser configuration information has long been collected by web analytics services in an effort to accurately measure real human web traffic and discount various forms of click fraud.
With the assistance of client-side scripting languages, collection of much more esoteric parameters is possible. In , EFF measured at least This article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November and incorporated under the "relicensing" terms of the GFDL , version 1.
From Wikipedia, the free encyclopedia. Small pieces of data stored by a web browser while on a website. For other uses, see Cookie disambiguation.
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Main article: Cross-site scripting. Main article: Cross-site request forgery. Main article: Web storage. Main article: Web cache. Main article: Device fingerprint.
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The name is then stored in a cookie. First, we create a function that stores the name of the visitor in a cookie variable:.
The parameters of the function above are the name of the cookie cname , the value of the cookie cvalue , and the number of days until the cookie should expire exdays.
If this is blank, the cookie will expire when the visitor quits the browser. This may be blank if you want to retrieve the cookie from any directory or page.
If this field is blank, no such restriction exists. Cookies were originally designed for CGI programming. The data contained in a cookie is automatically transmitted between the web browser and the web server, so CGI scripts on the server can read and write cookie values that are stored on the client.
Copyright by Refsnes Data. All Rights Reserved. Typically, it's used to tell if two requests came from the same browser — keeping a user logged-in, for example.
It remembers stateful information for the stateless HTTP protocol. Cookies were once used for general client-side storage.
While this was legitimate when they were the only way to store data on the client, it is now recommended to use modern storage APIs.
Cookies are sent with every request, so they can worsen performance especially for mobile data connections. To see stored cookies and other storage that a web page can use , you can enable the Storage Inspector in Developer Tools and select Cookies from the storage tree.
The cookie is usually stored by the browser, and then the cookie is sent with requests made to the same server inside a Cookie HTTP header.
An expiration date or duration can be specified, after which the cookie is no longer sent. Additional restrictions to a specific domain and path can be set, limiting where the cookie is sent.
For details about the header attributes mentioned below, refer to the Set-Cookie reference article. A simple cookie is set like this:.
Then, with every subsequent request to the server, the browser sends back all previously stored cookies to the server using the Cookie header.