When web browsers connect to websites, they send a user agent, which identifies the browser and the rendering capabilities it possesses. + The web server can use this information to decide which version of the website to send to the browser. + For example, many websites have different versions for desktop and mobile browsers.
+ +By default, Privacy Browser uses its own user agent, which is PrivacyBrowser/1.0. This sends a minimum of information to the web server.
+ Because web servers do not recognize this to be a mobile user agent, they typically display the desktop version of the site.
By comparison, WebViewâs default user agent divulges a large amount of information about the hardware and software of the device. + On the Settings screen, selecting WebView Default as the User agent displays the user agent that will be sent. + The screenshot below shows a Pixel 2 XL running Android 10 with Android System WebView 84.0.4147.125 installed. + Most web servers will recognize this as a mobile browser and will display the mobile version of the site if they have one.
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+ There is enough information in the user agent that sometimes only a few visitors to a website will be the same. + If the user agent is combined with another piece of non-unique identifying information, often it results in a unique fingerprint. + The Electronic Frontier Foundation created a tool called Panopticlick to demonstrate how much information can be gleaned from these sources. + If this test is run with JavaScript enabled the amount of information that is disclosed increases greatly. + Browser Leaks and Am I Unique are also good sources of information on this topic.
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+ There are several preset user agents that match common browsers and operating systems. For browser fingerprinting purposes, anything that is rare is easier to track.
+ If Privacy Browser becomes common and many people use PrivacyBrowser/1.0 as their user agent, it will be a good choice for privacy.
+ Firefox or Chrome are the most common user agents, but they auto-update and their version numbers change so quickly that it is likely the user agents included in Privacy Browser
+ will often be out of step with the majority of user agents in the server logs.
Some websites do not function correctly if they do not recognize the user agent. + Using domain settings to set the user agent to WebView Default, or another user agent that is commonly recognized, usually resolves the problem. + Androidâs WebView does not allow the user agent to be blank. If it is, WebView simply sends the default user agent to the server.
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