If you have a shared computer and you think that by deleting the history you can eliminate all traces of the pages you have visited, you are making a mistake.
How to View Your Browsing History in Incognito Mode
Although we use the incognito modeoffered by most web browsers, the truth is that there is always a loophole where all those “private” visits are recorded, and that isthe DNS cache.
What is DNS cache exactly?
When we write the name of a web page in the address bar of the browser, it goes to the DNS server that we have configured in our device to know what IP it corresponds to and load the content of the page.
Thus, when we later try to access that same site, our browser consults the DNS cache, and if it is in the list, it resolves the address without having to consult the IP address on the server.
This is a pretty smart trick that allows us to navigate and load the pages much faster, in addition to sending emails and performing other types of actions through the Internet.
The funny thing about all this is that the DNS cachedoes not distinguish between the different types of browsing, and records everything: both normal tabs and those that work in “incognito mode“.
How to see the websites that we have visited in incognito mode from the DNS cache
Since DNS is totally independent of the browser we are using, this is a trick that we can apply both for the websites visited inChrome, such as Firefox, Edge, Opera or any other browser.
To consult the list of pages registered in the DNS cache, all we have to do is execute a command from an MS-DOS or Powershell window on the computer.
- We open an MS-DOS windowin Windows by typing the command ”cmd” in the search engine on the taskbar. If we have an older version of Windows we can also enter this same command from ”Start -> Run“.
- Terminal windows usually open to the path where the active user profile is located, such as “C: \ Users \ User_name”. The first thing we are going to do is go tothe desktop,writing the command ”cd desktop“.
- Next, we write the command ”ipconfig / displaydns> historialdns.txt“. This will cause the system to dump all DNS cached history into a text file called “historialdns.txt”.
- Now we only have to go to the desktop and open the text file that has just been created. We will see how a list appears withall the web pages and services that we haverecentlyvisited, including those “private” webs that have been loaded in incognito mode.
Note: We can also see the contents of the DNS cache directly from the MS-DOS window by typing the command ”ipconfig / displaydns“.
However, the cache usually includes a large number of entries and in many cases it is not practical to consult, so I personally think that it is much more comfortable to dump it in a TXT file.
How to flush the DNS cache
If we are concerned that someone might spy on us with this method, we can always clear the DNS cache. To do this, just open a new MS-DOS window and execute the command “ipconfig / flushdns”.
In general, it is recommended to clear the DNS cache from time to time for both security and privacy reasons.
However, it can also help us solve technical problems, in the event that a page does not load correctly or shows any DNS errors.
If we are Android users, although we cannot see the content of the DNS resolution cache, we can empty it by simplyturning off the phone for at least a minuteand turning the device back on. If we do not want to turn off the mobile we can also do the following if we use the Chrome browser:
- Open Google Chrome and in the address bar write this URL:
- chrome: // net-internals /
- This will take you to a configuration screen where you must click on «DNS.
- To finish, select «Clear host cache.
How to disable Chrome’s incognito mode
If you have children at home and you want to deactivate the incognito mode of the browser, you will be interested to know that this is something that can be done. However, it is a delicate task, since it requires us to make a modification in the Windows registry editor.
- Press the “Win + R” key combination or click on the search engine on the taskbar and type the command ”regedit” (without quotes) to open the Registry Editor.
- From the drop-down menu on the left, navigate to the path ”Computer \ HKEY_LOCAL_MACHINE \ SOFTWARE \ Policies \“.
Now what we will do is create a new entry in the registry called “IncognitoModeAvailability” following these steps:
- Right click on ”Policies” and select “New -> Password”.
- Write ”Google” (without quotes) as the name that this new key or folder will have.
- Right click on “Google” and choose “New -> Password”.
- In this case, the new key will be called ”Chrome” (without quotes). In the end we should have a folder structure like this:
- Now we right click on «Chrome» and select «New -> DWORD value (32 bits).
- We will call this new value ”IncognitoModeAvailability” (without quotes).
- Finally, right click on “IncognitoModeAvailability”, select “Modify” and in the “Value information” field replace 0 with the number 1.
- Save the changes by clicking on the “Accept” button.
- Close the Windows registry editor and restart the Chrome browser.
From here, if we try to open a new incognito window we will see that Chrome no longer offers this option. It won’t even work by using the keyboard shortcut “Control + Shift + N” to open a new incognito window. The functionality will simply be blocked and inaccessible.
If at any time we want to re-enable incognito mode, we will only have to go back to the registry editor and modify the value of “IncognitoModeAvailability” to “0” so that it is available again.