some websites won't load or missbehave with privacy browser

Added by hugo gogo almost 2 years ago

Hi, i'm using PB version 3.11 on android version 6.0.1, from fdroid

I had difficulties on several website, so i made the settings the less specific i could (enable js, enable cookies, enable dom storage, enable form data, and disabled all incognito mode and blocklists modes) -> now there is no point to use PB anymore ;) but it didn't act better... (i've shutdown the app and reopen it)

if i try to go, say, to this page :, it won't show me anything but a message that the output would be better with javascript enable, but js is enabled

on this other website,, i keep having a message that check if i'm a human not a robot, like every three minutes (they tell me the cause could be one of three : either i click faster than a human, which i really don't :p, or something is blocking js, which is not true since i changed the settings, or a robot is on the same ip than me, well in that case i would have the same probleme when i use another browser, but i don't)

but then, i don't understand anything to this app so i might be doing lots of things wrong : for exemple in the settings i can choose another user agent than privacy browser, for exemple firefox for android, then it works with those websites, but i never installed firefox, and why can i choose to use firefox (and chrome and safari and chromium and so on) inside the PB app, what is going on that i don't understand ?

And now that i have opened the first webpage ( with firefox as a user agent, i can open it with PB as a user agent, even after cleaning all the cookies, why is that ?

i know that's a lot of questions, maybe not related one to another, if it's too much trouble to answer all of that don't bother, i will keep looking for solutions by myself, I say that because i see that you, Soren Stoutner, are the only one to answer on this forum, and also the dev of the app, so i understand that you cannot do a personal answer to every people having trouble using the app

Replies (6)

RE: some websites won't load or missbehave with privacy browser - Added by Soren Stoutner almost 2 years ago

The core to understanding this is that websites can do whatever they like. Each one chooses to do different things. Often they don't like to work if you do things to prevent them from tracking you and selling your information to third parties.

Your options are:

1. Allow them to track you because the website either does something you really want (more than you want to not be tracked) or you trust them to not do bad things with the information.

2. Try to get the web developer to change the way the website works. (As Privacy Browser becomes more popular, I think some developers will start testing to make sure they work with it using default settings.)

3. Stop using that website.

In general, there are several things that can cause a website to not work correctly. You can use domain settings to modify the settings for these sites while using the defaults for the general internet.

  • Javascript.
  • Cookies (generally required for logging in to a site, as the cookie is what keeps you logged in as you move between pages, although it should be possible to handle this differently by, for example, using the TLS session to maintain logins).
  • DOM storage.
  • A user agent the website recognizes.
  • Disabling the blocklists (which block a lot of the JavaScript that sites want to load).
  • They don't like your IP address (for all types of reasons, including because your IP address is a Tor exit node or comes from a VPN or is from a certain country).

These are the common ones, but websites can choose to use anything. For example, they can refuse to work if they don't like your screen size, or if you don't have a font installed they want, or just about anything else you can imagine. It is often hard to tell for sure what logic a particular website is using, although trial and error can get you there most of the time.

RE: some websites won't load or missbehave with privacy browser - Added by hugo gogo almost 2 years ago

i have gone through a process of trial and errors, and the only thing listed in your response that can explain the difficulties i have, is that those websites doesn't recognize pirvacy-browser as a user-agent, even with js and cookies and dom storage enabled, and blocklists desabled, and without changing my ip from a test on the same websites with another browser.

using firefox, or chrome, as a user-agent, fix another "bug" : the size of the windows display, which was wrong with privacy-browser as a user-agent (maybe it's intentional, to hide this information to the website ? but then, it makes it sometimes impossible to use, both in normal or wide-viewport mode)

ho ok now I understand : the user-agent settings refers exactly to the User-Agent http request header field ! by selecting "firefox for android" in the settings, i'm just modifying this request header, is that right ? it's not that you are really using firefox or chrome under privacy-browser, how could that be, since the size of the app is so small anyway

so i'm not lowering the security by selecting firefox as user-agent, am i ?

RE: some websites won't load or missbehave with privacy browser - Added by Soren Stoutner almost 2 years ago

User agents are often the issue. You can read a little about them in Guide > User Agent inside the app, as well as at

In the long run I plan to make the default in Privacy Browser be not sending a user agent at all. Not only is that currently not possible with Android's System WebView, but most websites will refuse to work if they do not receive a user agent. However, I expect the internet to change its mind on this issue at some point in the future, and I hope to be one of the reasons it does.

Anytime you send a user agent, you give a web server additional information with which to fingerprint your browser, which can allow them to uniquely identify you the next time you visit. You can read a little about this at If you send a user agent that isn't actually you, like Firefox on Android (currently Mozilla/5.0 (Android 12; Mobile; rv:102.0) Gecko/102.0 Firefox/102.0) when you are using Privacy Browser, it is easily for the web server to see that your browser behaves a whole lot different than Firefox 102.0 in hundreds of little ways. For example, Privacy Browser handles the Referer header differently than Firefox. It's third-party cookie settings are different. The subset of HTML 5 commands that it supports are different ( And on, and on, and on. This means that the web server can say, "I only have one person visiting my site that says they are Firefox 102.0, but are really running a different browser. I can tell every time they visit, so I always know it is them, even though they delete all their cookies.

That being said, there are currently a lot of easier ways a website can track users than to fingerprint browser behavior to see if it matches the user agent. Particularly, if you have enabled JavaScript, then worrying about the user agent should be far down on your list of priorities.

RE: some websites won't load or missbehave with privacy browser - Added by hugo gogo almost 2 years ago

ok i see :)

that's a shame, because most (if not all ?) websites uses js and or cookies !
even this forum, if visited on phone we need js to open the burger menu, and then we can disable js but we need cookies for the signing process to works

thx for the docs !

RE: some websites won't load or missbehave with privacy browser - Added by Soren Stoutner almost 2 years ago

Yes, it is going to take a lot of work to get the internet to rewrite itself to work correctly without JavaScript, and even more to get logins to work without cookies (a little tricky if the quality of the internet connection is inconsistent).

At some point I might contribute to the Redmine project to make things like the hamburger menu function without JavaScript as there is no reason to use JavaScript for that. Simple HTML 5 and CSS are sufficient.

RE: some websites won't load or missbehave with privacy browser - Added by hugo gogo almost 2 years ago

i agree, burger menu can easily work with just html and css, i've made several myself, but the problem is how the content of the menu is generated, i guess it depends of the back end, the content must be send at the time of the creation of the page, instead of being created at the time of the button click, i think

as for the javascript, i believe it can happen one day that internet will be more safe, i see more and more devs (even though still a minority) speaking about avoiding javascript

one good reasons i've heard to use javascript was to limit the loading of images, for both economical and ecological motivations. but i believe there could be good workarounds with css only, maybe with iframes or objects ? i don't really know :p