URL checker links reports are a lot like SEO audits: you get a large list of things you could fix, but the reality is that a lot of them are mostly functioning and you have to make some decisions about what you'll prioritize fixing.
Some sites will always throw a particular code (particularly the 300-level codes). Working with your report means figuring out what those are so you can ignore that noise.
Here are some general best practices to consider as you review your report.
General code guidance
In general, 400- and 500-level codes signify broken links, while most 300-levels are redirects that load successfully. But that's not always true.
While you might want to spot-check a few of them, ignoring 401 or 403 codes is likely a safe choice. Most of the 403 errors we investigated seemed to be perfectly functioning pages, and we now filter out these codes when we review our own reports.
Learn your false errors
You may also learn that certain errors seem tied to certain sites and aren't "real" broken links. We've noticed in our own testing that certain domains throw some errors on all URLs, even valid ones. In most cases, this is because the domains or sites block the kinds of automated requests our URL checker makes to check the status code.
For example: We reference Google documentation a lot. Basically every link to Google documentation throws a 404 error. If we view the pages in our browser, they usually load fine. Google seems to like to prevent automated URL checking, so we manually review these URLs periodically.
Let us know how we can help
If you're confused about a particular code or what's happening with a page, contact us and we'll try to help you make sense of it.