There are a number of factors that could impact the page speed. For instance, your internet speed and the server response time. Among all the factors, there is one that usually gets overlooked - the image file size.
When a browser first loads a page, it downloads all content of that specific page. If a page contains heavy content, for example, it has lots of images and text, it will greatly affect the page speed as well as the browsing experience. Page speed has become an important factor in the search engine ranking. To reduce a page load time, try to spread out the content on your website. For example, if you have 100 images to upload, instead of creating one single gallery with 100 images, you can create galleries with different themes.
Here are a couple of tips that could make your website load faster:
Upload smaller size images: Smaller size images require less time to load. The size limit of an uploaded image is 12 MB in Portfoliobox.
Adjust the image quality: The higher quality your images have, the heavier the files would be. You could speed up the loading of your website by slightly reducing your image quality. In Portfoliobox, you can adjust the image quality by clicking on the Cogwheel Icon > Settings > General > Website > Image Quality. The image quality scale is from -1 to 1. -1 is the lowest and 1 is the highest.