Available for Google chrome and Mozilla Firefox (and compatible with Microsoft Edge as well), Magnifying Glass (Hover Zoom) is a simple browser extension that allows you to magnify a limited area of a web page. It can therefore simulate what happens to the layout of your web page (spacing, font sizes, positioning, margins, ETC.) when a user visits it using certain assistive technologies (such as screen magnifiers).
Web Content Accessibility Guidelines (WCAG) starting from conformance level AA require you take appropriate actions to accommodate the needs of low vision users (which may be shared by people with other disabilities as well!).