Glassdoor gives you a look inside companies before you apply. Employees anonymously review their workplaces, rate things like work-life balance and compensation, and share salary information. The site also collects interview questions and reports on the interview experience, which can help you prepare. For anyone researching a potential employer, it's a way to see beyond the official careers page.

The anonymity means some reviews are written in frustration, and not every company has enough data for a reliable picture. But when there are dozens or hundreds of reviews, the patterns become useful. Glassdoor also publishes annual lists like Best Places to Work and offers salary calculators. A free account lets you browse most content, while employers pay for recruiting tools. It's widely used by job seekers in tech, finance, and other professional fields.