Now, you won’t feel perplexed anymore regarding what to do with the backlinks of broken links, because Google webmaster tool will now show the broken links along with their sources, so that you can request the webmasters of corresponding sites to change links to your site.
This would really help the readers to find the content of their interest, rather than getting annoyed on finding “Not Found” pages, because generally what happens is when someone requests a page that doesn’t exist, they end up with 404 error message (if there is no customized error pages). Now, Crawl error sources make the process of tracking down the causes of “Not found” errors quite easy. This helps you improve the user experience on your site.
You would be able to find the broken links on Google Webmaster Tools for your site in following way.
1. Go to Dashboard > Diagnostics > Web crawl
2. Click on “Not Found”
3. Click on the “Linked From” column
For every error in these reports, the “Linked From” column now lists the number of pages that link to a specific “Not found” URL.
You can also find errors in the Google Sitemap and the corresponding sources from the “Linked From” column.
The “Linked From” column gives the number of backlinks to your broken link. To view those backlinks, click on that result. On clicking it, opens a separate dialog box which lists each page that linked to this URL. It also gives the date when it was discovered. The source URL for the 404 error can be within or external to your site. One can also download the data by clicking on “Download all sources of errors on this site”.
Thus, from the sources, you could find out whether the cause is from your site or other’s and hence work accordingly. Put redirects on your site to appropriate url.