Mullvad LibreWolf Zen GNU_IceCat Floorp FireDragon Midori Dot Waterfox (Tor maybe) Guide to Running PWAsForFirefox Software with The Your Browser's Engine

[universish]

In this guide, I will explain how to run PWAs without using the Firefox browser engine/runtime folder from PWAsForFirefox.
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We will run PWAs using the engine/runtime capabilities of the browser you have installed (excluding the Firefox browser).
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We will do this by synchronizing the “runtime” folder.

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This guide will use Mullvad Browser Portable as an example:

PWAs working with Mullvad Browser (I guess this is a portable program) using the MSI installation of PWAsForFirefox.

Here is the step-by-step solution for Windows users:

1. Link Mullvad Browser as the Runtime

Instead of downloading a separate runtime or fighting with config.json paths, I mapped the runtime folder directly to Mullvad's internal browser folder.

• Close Mullvad Browser.
• Open Command Prompt (CMD) as Administrator.
• Run the following commands (Adjust the Mullvad path to your installation location):

i. Remove existing runtime folder if it exists

rmdir /s /q "%AppData%\FirefoxPWA\runtime"

ii. Open the directory where Mullvad Browser is located.
“C:<bla_bla>\Mullvad Browser\Browser”
Copy the mullvadbrowser.exe file and paste it next to the “mullvadbrowser.exe” file.
Rename the copied file, such as “mullvadbrowser_copy.exe,” to firefox.exe.

iii. Create a Junction Link pointing to Mullvad's (runtime) engine
NOTE: Make sure to point to the 'Browser' folder inside Mullvad, where mullvadbrowser.exe resides:
.
.
mklink /J "%AppData%\FirefoxPWA\runtime" "C:\<bla_bla>\Mullvad Browser\Browser"
.
.

2. Bypass "Downgrade Protection" & Version Errors

When using an existing browser as a runtime, Firefox might throw a "You are using an older version of Firefox" error or refuse to launch the profile. To fix this, we need to allow downgrades globally.

• Open System Properties -> Environment Variables.
• Under User variables, click New.
• Variable name: MOZ_ALLOW_DOWNGRADE
• Variable value: 1
• Click OK.

3. Install the PWA

• Open Mullvad Browser.
• Go to the website (e.g., Tuta Mail).
• Click the PWAsForFirefox extension icon -> Install Current Site.
• It should now install instantly without asking to download a runtime.

4. Transfer Mullvad Settings & Extensions (Hardening)

• By default, the PWA creates a fresh, empty profile. To get Mullvad's privacy settings (user.js), themes, and extensions (PrivacyBadger, TWP, OptMeowt etc.) into the PWA:
• Source: Go to your Mullvad installation folder: C:\<bla_bla>\Mullvad Browser\Data\Profiles\<bla_bla_bla>.default-release
• Copy these three items: user.js (Critical for privacy/hardening); prefs.js (General preferences); extensions (Folder).
• Destination: Go to the PWA profile folder: %AppData%\FirefoxPWA\profiles\YOUR_PWA_PROFILE_ID\ . Default Profile folder: %AppData%\FirefoxPWA\profiles\00000000000000000000000000
• Paste and replace the existing files.
• Now the PWA launches with the full Mullvad security configuration and extensions.

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I performed the same process using the PWAsForFirefox portable version managed by PortableApps.com. Only the file locations change in that version. Everything else remains the same.

1. Do not uninstall the PWAsForFirefox (msi) executable program. Your PWAs, PWA settings, and PWA extensions will be deleted.
2. Download the “PortableApps.com_Platform_Setup_.paf.exe” file from the Portable Apps official website or the official sourceforge mirror.
3. Download the “firefoxpwa__online.paf.exe” file from the official repository. (If you cannot see the paf portable file in the list, click the “Show all 15 assets” button.)
4. Always verify the hash of the software you download. If you are looking for an easy method, download the executable or standalone file of the GtkHash software from the official repository. Install it or extract the standalone file. Then run it. Select the file and calculate the hash value. If you paste the hash code/hash value into the hash code box below, you can see that it has been verified with a green check mark.
5. Run and install the “PortableApps.com_Platform_Setup_.paf.exe” software.
6. Run the PortableApps.com Platform software. If it doesn't work, run Start.exe. Click on the icon in the taskbar at the bottom right.
7. Click on “Manage Programs” --> “Install New Application [paf.exe]”.
8. Select the “firefoxpwa__online.paf.exe” file. It will install.
9. If the “PWAsForFirefox” portable program is running, find the “PWAsForFirefox” icon in the taskbar at the bottom right.
10. Right-click on the “PWAsForFirefox” software --> Click on “Exit”.
11. Find out the location/directory where the “PWAsForFirefox” Portable program is installed. “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable”
12. Find the runtime directory. “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox\runtime”
13. Delete the “runtime” folder.
14. Find the files of the installed PWAsForFirefox. “C:\Users<username>\AppData\Roaming\PWAsForFirefox”
15. Copy the “profiles” folder and all other files and folders (except for the config.json file) except runtime, and paste them into the “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\Data” directory.
16. Delete the “runtime” folder or the ‘runtime’ sync shortcut (mklink) folder in the “C:\Users<username>\AppData\Roaming\PWAsForFirefox” directory.
17. Uninstall/delete the installed PWAsForFirefox (msi) program (the non-portable program).
18. Locate the mullvad directory. “C:<bla_bla_bla_bla_bla>\Mullvad Browser\Browser”
19. Copy and paste the “mullvadbrowser.exe” file and rename the copy to “Firefox.exe”.
20. Run CMD as administrator.
21. Run the command mklink /J “C:\<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox\runtime” “C:\<bla_bla>\Mullvad Browser\Browser”.
    This command creates a synchronized shortcut folder named “runtime” inside the “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox” directory. It synchronizes the files and folders in the “C:<bla_bla_bla_bla_bla>\Mullvad Browser\Browser\” directory of the Mullvad browser with the “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox\runtime” directory.
22. Open System Properties -> Environment Variables.
23. Under User variables, click New.
24. Variable name: MOZ_ALLOW_DOWNGRADE
25. Variable value: 1
26. Click OK.
27. Click on the “PWAsForFirefox” software to run/start it.
28. Launch your Mullvad personal portable browser and check your PWAs. Enjoy!

These instructions are what you need to do after installing the PWAsForFirefox software using the “PWAsForFirefox<bla..bla>.msi” file, as I explained step by step earlier.

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If you have never installed the PWAsForFirefox executable software, follow these steps.

1. Download the “PortableApps.com_Platform_Setup_.paf.exe” file from the Portable Apps official website or the official sourceforge mirror.
2. Download the “firefoxpwa__online.paf.exe” file from the official repository. (If you cannot see the paf portable file in the list, click the “Show all 15 assets” button.)
3. Always verify the hash of the software you download. If you are looking for an easy method, download the executable or standalone file of the GtkHash software from the official repository. Install it or extract the standalone file. Then run it. Select the file and calculate its hash value. If you paste the hash code/hash value into the hash code box below, you can see that it has been verified with a green check mark.
4. Run and install the “PortableApps.com_Platform_Setup_.paf.exe” software.
5. Run the PortableApps.com Platform software. If it doesn't work, run Start.exe. Click on the icon in the taskbar at the bottom right.
6. Click on “Manage Programs” --> “Install New Application [paf.exe]”.
7. Select the “firefoxpwa__online.paf.exe” file. It will install.
8. If the “PWAsForFirefox” portable program is running, find the “PWAsForFirefox” icon in the taskbar at the bottom right.
9. Right-click on the “PWAsForFirefox” software --> Click “Exit”.
10. Find out the location/directory where the “PWAsForFirefox” Portable program is installed. “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable”
11. Find the Mullvad browser directory. “C:<bla_bla_bla_bla_bla>\Mullvad Browser\Browser”
12. Copy and paste the “mullvadbrowser.exe” file and rename the copy to “Firefox.exe”.
13. Run CMD as administrator.
14. Run the command mklink /J “C:\<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox\runtime” “C:\<bla_bla>\Mullvad Browser\Browser”.
    This command creates a synchronized shortcut folder named “runtime” inside the “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox” directory. It synchronizes the files and folders in the “C:<bla_bla_bla_bla_bla>\Mullvad Browser\Browser\” directory of the Mullvad browser with the “C:<bla_bla_bla>\PortableApps\PWAsForFirefoxPortable\App\PWAsForFirefox\runtime” directory.
15. Open System Properties -> Environment Variables.
16. Under User variables, click New.
17. Variable name: MOZ_ALLOW_DOWNGRADE
18. Variable value: 1
19. Click OK.
20. Click on the “PWAsForFirefox” software to run/start it.
21. Launch your Mullvad personal portable browser and load your PWAs.
22. Enjoy!