What is "Block Site" extension and how does it work?

This extension monitors top-level hostname accesses and matches them with a user-defined blocking list. If a hostname is matched, then the access is blocked just before your browser sends the top hostname request to the server. This is useful to prevent access of a hostname that is not supposed to be accessed from your IP address for instance or to prevent popup websites from opening new tabs and hence injecting malicious scripts into your browser.

The extension also can be used as a URL redirector. To use the extension in the redirecting mode, add a hostname to the blocking list from the options page. Then enter the FULL URL of the destination domain in the redirect box (with schemes like "http://www.google.com"). Note that the extension extracts the arguments of the original URL and passes them to the destination URL. This feature is useful to redirect for instance search results from Google.com to Bing.com. To do so add "*.google.com" as a new hostname and in the destination filed add "https://www.bing.com". Press the save button for the changes to take place. Now search something in the address bar and you will get the result from Bing.com.

Note: If it is important that the blocked remote servers do not receive any connection requests, make sure to uncheck "Display title of blocked hostnames" item in the options page. When this item is checked, the extension will send a request to the server and ask for the actual title of the page. This option is useful to distinguish blocked tabs only if there is no restriction to send or receive data from the blocked hostnames.

recommended "Password Lock for WhatsApp Web" extension for Chrome, Edge, and Firefox browsers

This extension adds a password protection feature to your WhatsApp Web. It requires the user to enter a password to access the interface, and can also automatically lock the interface when the computer is inactive for extra security. Read more here.

What is the master password and how can I set it?

If a master password is set from the options page, you can browse the restricted URL for a pre-defined time period. Also, changing the options (like removing a hostname form the blocking list or changing the time interval of temporary hostname whitelisting) will require the password first. This is mainly useful if you want to prevent other users of the computer to change important settings from the options page.

Note that by having the master password set, you can browse the blocked websites by entering the master password in the box when a block page is displayed. This will unblock a hostname temporarily for a pre-defined period (1 minute by default).

How can I block all the sub-domains of a single domain (like www.google.com, ca.google.com, ...)?

Use wildcard in the place of the subdomain. For instance, to block all the Google subdomains use "*.google.com". Here is the list of valid and invalid wildcard matchings:

When a wildcard is used in a matching pattern, the destination redirection feature is disabled. Why?

This is due to performance drawback of wildcard matching. Wildcard matching is computationally costly and hence this extension does not allow it! You can add multiple rules without wildcard to have the same matching power but without performance drawback.

What's new in this version?

Please check the Logs section.

Can I change the theme of the blocked pages?

Yes, as of version 0.1.1, it is possible to choose between dark and light themes. The theme selector is a button that is placed on the top right side of the blocked pages. This option is persistent across browser restarts

Can I block websites for a defined period of time only?

As of version 0.1.3, there is a new section in the options page to define the time period and days which the blocker is working. Fill this section to block the list for the defined period only. You can also remove a day from the list of days if you want to allow unblocking for that particular day.

Can I use this extension to only allow a few hostnames to be opened and all other hostnames get blocked?

There is a reverse mode in the options page. If this option is checked, only hostnames that are listed in the list can pass the blockage and all other hostnames will be blocked.

How can I prevent this extension from being removed or disabled from the Firefox browser?

Create a policies.json file with the following content. This file sits into a directory called distribution within the Firefox installation directory. You can use it to control how users have access to the browser features. For more info visit github.com/mozilla/policy-templates

{
  "policies": {
    "Extensions": {
      "Locked":  ["{54e2eb33-18eb-46ad-a4e4-1329c29f6e17}"]
    }
  }
}

I have a big list of hostnames to be blocked. Can I import them instead of manually adding new rules?

Create a text file anywhere on your computer. Let's call it block.txt. The content of this file is a line-separated list of hostnames to be blocked. Basically, each hostname is placed in a new line. If you would like to add comments, use a new line and start the line with "#" character. The extension simply ignores these lines. If you need to enable redirection, add the complete path to the redirected page after the hostname to be blocked. Note that after using the import button, the list will be added to the rules, but still it is not being applied. You need to press the "Save" button for the changes to actually apply. If for any reason, you would prefer to start over, simply close the options page and reopen it. See the sample below:

  

    
# Line-separated list of hostnames to be blocked. Lines start with "#" are ignored
  
  

    
# hostname to be blocked
    
URL to be redirected to (optional)
  
  

    

  
  

    
www.google.com
    
https://www.bing.com
  
  

    
www.yahoo.com
    

  

Is it possible to pause the blocking for a period instead of using the schedule option? Like when you need to temporary access all the websites for some time.

Yes, as of version 0.2.3, you can use the right-click context menu over the toolbar button to pause the blocking for a specified period. If your block site is password-protected, you will be asked to unblock the extension first. If pausing is not needed anymore, use the resume item to in the right-click context menu to resume the normal behavior.

Is it possible to have per-domain schedules instead of one schedule that works for all websites?

As of version 0.2.3, there is a new field on the options page to allow specifying a regular expression rule when defining the scheduling time. If this field is available,the extension only applies the rule to the URLs that match the rule. Otherwise, the global scheduling time is used (if available). To update a schedule with a rule, you need to first load the schedule. To do so enter the rule in the box and wait for the extension to load the information. To delete a schedule with a rule, again enter the rule and wait for the extension to load the rule for you. Then delete the time section and keep the rule so that the extension knows that you want to delete the rule. Now press the save button. Alternatively, you can download all the settings as a JSON object and then modify them with a text editor, then load them back to the extension.

Here is a minimal example to block Google.com on Mondays between 07:00 AM to 08:00 AM. Note that the "google.com" hostname is listed on the blocked list as well as it matches to a regular expression in the scheduling list.

{
  "blocked": [
    "google.com",
    "*.google.com"
  ],
  ...
  "schedules": {
    "google\\.com": {
      "times": {
        "Mon": [
          {
            "end": "08:00",
            "start": "07:00"
          }
        ]
      }
    }
  },
  ...
}

Is it possible to block a website based on a regular expression instead of wildcard matching?

As of version 0.2.3, you can define a regular expression rule in "Block a new hostname" filed by prepending the rule with R: keyword. This way the extension knows that a regular expression is inserted and hence does not apply the wildcard matching to your rule. Using regular expression you can fine-tune your blocking to match complex domains and keywords.

There is an annoying popup that opens itself once per while. Can I use this extension to automatically close the popup tab?

Yes, as of version 0.2.3, there is a special redirecting keyword that immediately closes a tab that matches a blocking rule. The keyword is close. So whenever you need to close a tab that is blocked by this extension, use this keyword as the redirection destination.

Is it possible to use this extension on a corporation to block sites on multiple machines?

As of version 0.3.2, this extension supports managed storage to import settings from the managed preference. An admin user can configure all instances of this extension by setting a managed storage. The PLIST for reading preferences looks like this example. Use your browser managed storage documentation to see how to set up the managed storage.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple/DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>json</key>
  <string>single-line valid JSON string containing all the preferences (use the output of the export button + shift key to generate this string)</string>
</dict>
</plist>

By default, this key is set to false, which causes the extension to overwrite all the preferences only once. If the value of this key is set to true, on each restart the extension overwrites all the preference from the provided JSON string. Note that in case the JSON string is updated by the admin (contains a new GUID), all the preferences will be overwritten once even if the "managed.storage.overwrite.on.start" key is set to false. Also, note that you can set a password while configuring the extension once and this password will prevent all the client machines from altering the preferences later (all clients only access to the HASH of the password so it is safe to set the password on the machine before generating the JSON file).

On the Firefox browser, you need to create a JSON file called {54e2eb33-18eb-46ad-a4e4-1329c29f6e17}.json and placed it inside the ManagedStorage directory. Read more about how to configure Firefox to use the managed storage here. Here is a sample JSON file to block Wikipedia:

{
  "name": "{54e2eb33-18eb-46ad-a4e4-1329c29f6e17}",
  "description": "managed storage for Block Site extension",
  "type": "storage",
  "data": {
    "json": "{\"blocked\":[\"wikipedia.org\",\"*.wikipedia.org\"],\"last-update\":1608787025230,\"managed.storage.overwrite.on.start\":true,\"guid\":\"5f956061-006d-4713-8e33-a2adb7136902\"}"
  }
}

Is there any way to have all sites blocked all hours of the day, except for one hour of the day where just one site is available?

Since we need to block all websites, you need to add a general blocking rule that matches every hostname (e.g. *://*/*). This rule makes sure to block all hostnames or it makes sure that the blocking module will consider all hostnames. Now we need to unblock a single hostname. We can do this by adding a scheduling rule for this hostname. This way before blocking is applied, the extension checks the schedule, and if the schedule does not match, the blocking is aborted. Say we want to block example.com all day long except between 01:00 and 02:00. We are going to add a schedule with the example\.com regular expression rule and set the "from" to 02:00 and set the "end" to 01:00 for all days.

I want to block an entire hostname (e.g. google.com), but I want to whitelist a single page of this hostname. Is it possible to do this with this extension?

To block an entire hostname, simply browse it and then press the action's button to automatically add the blocking rules for you. Now open the options page and add a new scheduled rule which supports regular expression. Let's say we want to unblock the search query for "cat" (e.g. https://www.google.com/search?q=cat). We are going to add a regular expression like google\.com.*cat to match google.com when the word "cat" exists, and will set the start date to 00:00 and the end time to 00:01. This way a page that matches this URL is only blocked for 1 minute a day and is unblocked otherwise, although the entire hostname is blocked. As an alternative approach, you can also directly write a regular expression that matches the entire hostname and does not match when a keyword exists.

To bypass blocking, a user can delete the internal storage of the browser. Is there a way to prevent this?

All browsers use a local directory to store all the profile data such as storage, bookmarks, password. In your operating system, you can protect an individual directory so that it can be read-only by a user while having the write access by the other user. To protect the profile directory, create a user with write permission to this directory. Always login with the user that has read-only access to the directory and run your browser from the user with write access. On Linux use "su rw_user -c chrome" for instance.

Can I schedule blocking in a different time zone? For privacy reasons, I configured my browser in GMT, which does not match my local timezone.

As of version 0.4.1, there is a new option on the "Schedule Blocking" section on the options page to configure a custom offset in minutes. For your convenience, it also displays the calculated time after applying the offset.