Broken links can be caused by different problems:
- Misspelled URLs: Sometimes people make make mistake when they copy a URL into a A HREF tag.
- Malformatted URLs: Sometimes there are characters that modify the URL. For example, sometimes URLS are encoded with characters that the web server can’t interpret.
- non-latin basic ASCII characters in URLs: We found that many web servers could consider that a link was broken because characters that were not part of english alphabet like éèàûüôç
- Missing file: The file has been deleted
- Moved file: The file has been moved to another location
- Renamed file: The file has been renamed
All of those problems cause the same HTTP error code by the web server, a 404 “not found” error code