Broken internal links vs broken outbound links
Some experts would say that broken internal links which stop crawlers finding new pages on your site, are arguably worse than broken outbound links which are quite inevitable on large sites that have a lot of content and outbound links, for the key reason that it’s not only an error page for some users but it’s also a loss of indexing, traffic and sales.
It is always nice to find and fix outbound dead links, but it’s rarely a critical issue unless you have loads of them. That said, it’s one of the next best things to fix after more critical issues are resolved, as it shows you’re keeping on top of content, indeed keeping dead links is a sign of editorial neglect.
That said, other experts would say that broken outbound links are also arguably worse than broken internal links, because the potential for linking to something dangerous (malware for example) is significantly greater, and even if you don’t link to something dangerous, the fact that you have made a mistake in this way means you’re liable to do it even if you haven’t yet.
Infinite redirect loops
Aside from actually linking to malware via broken external links, we would say that infinite redirect loops are the worst kinds of broken links, as they are very similar in effect to broken links that take you to error pages, but slightly worse due to the lack of notification, links, search box, etc to help you understand the situation and find your way back to where you came from. When you’re in an infinite redirect loop, your browser’s own error page will be displayed instead of the site’s error page, if your browser notices the loop and doesn’t keep trying to reload the page like major browsers often used to.
Are redirect chains a big problem?
When a redirect is being used, and page A links to B which links to C, it’s not technically a broken link, as there is a join, so we call it a redirect chain, and it’s a very minor issue to update the link to point directly to the end destination. Updating these links will increase page loading speed and maximise link equity transfer, but it’s not as major as fixing actual broken links. In fact, when people use URL shortening tools they’re wilfully creating redirect chains.