Ad-blockers detect scripts designed to make your browser load content from the servers of ad networks. By blocking these scripts, the adverts aren’t requested or displayed. Ad-blockers can also block scripts that monitor your online behavior or contain malicious code. Ad-blockers are able to detect scripts by comparing them with huge lists of offending domains – often created by the online community.
Without these additional advertising requests playing out, pages tend to require less bandwidth and are quicker to download. Indeed, research suggests that the execution of third-party scripts can account for more than half of a page’s loading time.