Here's how you can set up a local web server environment using XAMPP (other web server environments are available) to preview Juicebox galleries locally in any web browser (without the need to change any browser settings).
(Instuctions are for Windows but should be similar for Linux and Mac.)

(1) Download the XAMPP installer from here: https://www.apachefriends.org/download.html

(2) Run the installer file to install XAMPP. Default settings are fine but you only need Apache and PHP (which are selected by default and cannot be deselected).

(3) Run XAMPP Control Panel.

(4) Start the Apache module (click the 'Start' button next to 'Apache' under 'Actions').

(5) Copy your Juicebox gallery folder to the C:\xampp\htdocs\ directory.

(6) Preview your gallery by opening your browser of choice and entering the following into the browser's address bar: localhost/gallery_folder_name/index.html

Tips:

(1) You can install the Apache module as a Windows service if you like (via the checkbox under the Service heading in the XAMPP Contol Panel) so that it automatically starts on boot (to save you from having to manually start the service each time you boot your computer).

(2) You can save your gallery folders directly to the C:\xampp\htdocs\ directory (on JuiceboxBuilder's 'Publish' tab) to save you from having to copy them there manually.