External Links leak page rank. Unlike inbound aka internal links , they decrease the page views. They're also responsible for high exit and bounce rate.
As people will click on the link and visit a third-party website, they'll spend less time on your website. The only benefit of an External link is that if the link is an affiliate link, you might earn a commission.
If you're linking your page to a third-party website, make sure that the website is trustworthy and relevant to the content on the page.
Too many external URLs is harmful to a website. Google may flag your website for selling/buying links. The Google Penguin algorithm targets websites engaged in unnatural link building techniques.
Like inbound URLs, it's difficult to keep a track of external links manually, but with this tool, this task is easy.
The Crawl Center External Link Checker tool will make you aware of the number of external URLs on a page. It will also display the URL's anchor text. Account registration is not required to use this tool. Enter the URL of page you want the tool to analyze and click the "Check" button. That's it!