The first thing to point out about portability is that not all browsers run on all operating systems. While { -brand-name-firefox }, { -brand-name-chrome } and { -brand-name-opera } work on all major systems and are easy to install, { -brand-name-ie }, { -brand-name-edge } and { -brand-name-safari } only work on { -brand-name-microsoft } and Apple’s own systems. The mobile version of { -brand-name-safari } is pre-installed on Apple’s mobile devices, and most { -brand-name-android } devices come with a pre-installed browser modified by the manufacturer for the device. { -brand-name-firefox }, { -brand-name-chrome }, { -brand-name-edge } and { -brand-name-opera } can easily be installed and even used side by side.

首先要提出的是，並非所有瀏覽器都能在所有作業系統運作。儘管很簡單就能在各主要作業系統安裝使用 { -brand-name-firefox }、{ -brand-name-chrome } 及 { -brand-name-opera }，但 { -brand-name-ie }、{ -brand-name-edge } 及 { -brand-name-safari } 僅能於 { -brand-name-microsoft } 或 Apple 系統中運作。Apple 行動裝置內建了內建行動版 { -brand-name-safari }，而大部分 { -brand-name-android } 裝置也內建由裝置製造商客製化的瀏覽器。也很簡單就能安裝 { -brand-name-firefox }、{ -brand-name-chrome }、{ -brand-name-edge } 與 { -brand-name-opera }，甚至可以同時使用。