Google Analytics can be used to find bad pages and links at your website. Here are the steps to get information about these issues so you can correct them and improve the user experience at your website.
Find Bad URLs and Broken Pages
Behavior > Site Content > Page Title dimension, filter for “Page Not Found”
If a visitor goes to a bad URL (a page that doesn’t exist) they arrive at the “404 Page Not Found” landing page. Visits to these bad URLs appear in the Site Content report as they all have different URLs. But they all have the same Page Title.
In Analytics, go to the Behavior > Site Content report. Switch to the Page Title dimension. Add the title of your 404 page into the filter box. You should now see a report with just one row: your page not found page.
Click on it to drill-down to see all the URLs that have resulted in a 404 error at your site. To fix the issues, redirect traffic from these pages to the most relevant page or create content using these URLs.
Next Find the Bad Links
Behavior > Site Content > Page Title dimension, filter for “Page Not Found” > Drill down > Navigation Summary, Previous Page Path
Using the 404 report, click on the “Navigation Summary” tab to see how people are getting to the bad page. The pages in the “Previous Page Path” list are pages with broken internal links. You’ll want to remove the link or update it to point to another page.