BittyWeb on Windows 10

Windows Version

Windows 10 is the only version of Windows supported by BittyWeb.


Chrome version 70 or later is required for use with Bitty Web on Windows 10 and currently is the only supported browser for use on Windows.

Your Browser Details


If you absolutely must use an earlier version of Chrome on Windows 10, then you must install a Chrome browser extension known as a polyfill.

Installing the polyfill is a little complicated and you should be confident in using and configuring a Windows PC if you decide to use that option. It does allow you to use older versions of the Chrome browser, however.

Using a polyfill with standard Chrome

Follow the installation instructions below to install the Web Bluetooth polyfill for Google Chrome on Windows 10. Users will need to be instructed to allow the browser to run in developer mode when they see a pop-up dialogue asking about this whenever they start Chrome.

Installing the Extension

1. Your computer must be running Windows 10 Creators Update (version 1703 / build 15063) or a newer release.

a) Press the Start key on your keyboard and then type "about". Select About your PC from the list.
b) Look for the Version under the Windows specification heading. Check that the version number is at least 1703.

2. Your computer must also have Visual C++ Redistributable for Visual Studio 2015 (x86) installed. To find out if it is already installed:

a) Press the Start key on your keyboard and then type "programs". Select Add or remove programs from the list.
b) Scroll through the list of installed programs, looking for Microsoft Visual C++ 2015 Redistributable (x86).

If you are sure you do not have it installed, download and install it from this Microsoft web page.

3. Download this zip file and extract its contents somewhere on your computer.

4. Open Chrome's extensions panel, enable developer mode and load the polyfill like this:

a) Open a new Chrome window (CTRL+N or CTRL+T) and enter the following into the address field at the top: chrome://extensions/

b) Enable developer mode and then click the "Load Unpacked" button. Navigate to and select the extension folder which you extracted from the downloaded zip file from step 3. Make a note of the ID which is displayed within the panel which now displays details of the Web Bluetooth extension you just installed.

If you get an error when you load the extension about the manifest file not being found or being unreadable, you probably selected the wrong folder. Make sure you select the extensions folder from the extracted zip file.

5. Install and configure the polyfill in Program Files (x86)

a) Create a folder called "Web Bluetooth Polyfill" inside C:\Program Files (x86)
Copy the files inside the BLEServer folder (from step 3) into C:\Program Files (x86)\Web Bluetooth Polyfill.

b) Edit C:\Program Files (x86)\Web Bluetooth Polyfill\manifest.json and change the extension id in the allowed_origins section to match the extension ID you noted down in step 4b.

c) Run C:\Program Files (x86)\Web Bluetooth Polyfill\register.cmd. This will register the polyfill within Windows.

6. Test using the Web Bluetooth Device Info sample by Google, here. Select the All Devices checkbox and make sure you have at least one micro:bit plugged in. You should see something like this:

with each micro:bit you have switched on, listed.


Try the troubleshooting tips suggested at

About The Polyfill

The Web Bluetooth Polyfill for Windows 10 was written by Uri Shaked and Bluetooth develoeprs and enthusiasts are most grateful for his work. The full code and supporting information for the polyfill can be found at