Collection of information

This is a summary of many little useful information. Be welcome to add information if you think they will help others!

Which Host lists are included in Blokada?

Here is the link to the file that includes all links to the Host lists selectable in Blokada: https://blokada.org/api/v4/content/en/filters.txt.
If you need to check whether a domain is included in a specific list, you will find the content of the lists very easily by searching the link to the Host list in this file:)

Which information gets send if ‘Reports’ is enabled?

Blokada doesn’t send a lot of data, only: device type and manufacturer, API level, Blokada version.

Where in the phone does Blokada store data?

iOS:
On iOS Blokada’s data is stored in user defaults / blokada.

Android:

full {
    // full lands on blokada.org.
    applicationId "org.blokada.origin.alarm"
}
community {
    // community lands on F-Droid and XDA Labs.
    applicationId "org.blokada.alarm"
}
google {
    // google build lands on Google Play.
    applicationId "org.blokada.alarm.dnschanger"
}

If you select request logger to log blocked / allowed / all requests. In Download / Blokada a file will appear called ‘requests.csv’.
If you want to add a Host list from local storage the file needs to be saved in Download / Blokada / filters.

In earlier versions there was a setting called with with one was able to have Blokada’s data in ‘internal or external’ storage. Careful, internal means in the internal app memory, which the user can’t access. External meant in the internal but user-accessable memory in the folder Download/ blokada.This setting is still available in the hidden mode.

Firewall feature on Android?

Not yet, but it’s planed for the future. Github requests to upvote:


How to figure out, which app accessed a specific domain?

There is a solution to this question if the user didn’t yet upgrade to Android 10:

One can use various apps to check which app requests which domain for example Net Monitor: https://f-droid.org/app/org.secuso.privacyfriendlynetmonitor.

On Github we have a feature request for implementing this function: https://github.com/blokadaorg/blokada/issues/418

How to get in touch with Host list maintainers?

Steven Black: https://github.com/StevenBlack/hosts
Jerryn70 (Goodbye Ads): https://t.me/goodbyeads and https://github.com/jerryn70/GoodbyeAds
Energized Protection: https://t.me/energizedprotection and https://github.com/EnergizedProtection/block/issues

Can’t grant VPN permission. Can’t click it.

If a user describes this behavior ask him to turn off any Screen dimmer, screen-overlay or Blue-light filter he might be using.
If that doesn’t help -> restart
If that doesn’t help -> (ask for screen dimmer etc. again and if nothing:) reinstall.

Update doesn’t show in F-Droid

Blokada’s new version is released on F-Droid but you don’t see the new update in F-Droid? Then you probably need to ‘update the repositories’ in F-Droid. To do this go to the first screen you see when opening F-Droid. There swipe to the bottom and wait until F-Droid has finished updating. Check again for updates in the bottom right corner.

The hidden mode on Android v4

The hidden mode re-enables the the display of settings that were excluded from the app for various valid reasons. Users are therefore not supposed to enable it again.
You CANNOT deactivate this mode again! You can enable it by long-tapping on the menu App settings until a Smiley appears. Restart Blokada and you will see the outdated settings.

Host lists on first install

v5 Energized Blu is preloaded. Ad blocking will work directly.
v4 Lists are not preloaded and need to be downloaded after enabling Blokada. Attention - if the user is on mobile data the list won’t be downloaded, as Ad blocking / Adblocking settings / Download on wifi is enabled by default as well.

Does it slow down your internet speed if you select more rules?

NO
First of all, yes, the look-up costs some time, but it doesn’t cost more time the more rules (so all domains that are supposed to be blocked) are selected. The reason for this is, that Blokada stores all rules in a hash map.
The time for checking a entry consists of multiple parts:

  1. Calculating the hash of the domain to check.
    The hash function used for strings in Kotlin/Java is rather simple and has a linear runtime in proportion to the strings length.
    As most domains have more or less even length this can be seen as a constant time.
  2. Calculating the index of the bucket that should contain the entry:
    This is just some really simple math. Calculating the remainder of the hash as a number divided by the number of buckets -> index of the bucket.
  3. Checking the entries of the bucket
    All entries in the bucket are checked. If there is no match the domain isn’t included. Most of the times a bucket should only contain 1 entry. If the hash function is really bad or the dataset is biased to create a lot of hash collisions a bucket could contain a lot of entries. As all entries in a bucket are organized as a linked list and are checked one by one this could affect runtime badly but for domains and the standard hash function this shouldn’t be the case.

Why is Youtube in ‘restricted mode’?

  • When Youtube is in restricted mode the comments will not be loaded and also some videos are not accessible (for more information about restricted mode: https://support.google.com/youtube/answer/174084 )
  • Some DNS Server (especially Adguard Family) redirect Youtube to it’s restricted mode. These DNS servers are usually family friendly DNS-servers.
  • To check if this could be the problem choose another DNS server and test if it works afterwards.

Links to check the status of DNS servers

Cloudflare: https://www.cloudflarestatus.com/
Adguard: https://status.adguard.com/

How to check which domain is included in which Host list

If you are on a Windows PC or the smartphone the easiest way to check this is to tap this link and search for the Host file you selected. Then just type ctrl+f and enter the domain you are looking for. Or use the regular search function.

On Linux you can download the file and run the command grep -F "domainname" filename.txt. (But this is more helpful, when searching for Errors or similar in the blokada.log)

How to detect where you downloaded Blokada for Android from

If you downloaded Blokada v4 from F-Droid or XDA in the menu About Blokada you will see ‘…community release…’ at the top of the menu.
Otherwise you downloaded Blokada from our website or a similar source.
Please only download Blokada from one of the sources mentioned in this article: Where can I download Blokada?

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Why is Youtube in ‘restricted mode’?

  • When Youtube is in restricted mode the comments will not be loaded and also some videos are not accessible (for more information about restricted mode: https://support.google.com/youtube/answer/174084 )
  • Some DNS Server redirect youtube to it’s restricted mode. These DNS servers are the family friendly dns-servers so far I know.
  • To check if this could be the problem choose another DNS server and test if it works afterwards.

@c_C could you add this to the starting article?

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In the DNS list available in Blokada, only adguard DNS (Family) enforces the restricted mode and safe search.

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