A 404 error is a standard HTTP status code that indicates your web browser was able to communicate with the server, but the server could not find the requested page. Let's take a look at 10 of the more common 404s you could encounter.

Tip: I've included their degree of severity, tips on how to address them, and tips on how to set redirects in HubSpot.

The Top 10 Causes of 404 Errors Are...

1. An incorrect URL was entered by the user

This happens when a user manually types a URL into the address bar and makes a typo. To fix this, ensure that all internal links on your website are correct and encourage users to bookmark their favourite pages.

(It's a typo: 1/5 severity)

2. Link to a password-protected page

If a link points to a page that is password-protected and the user hasn't already entered the password (saved in a cookie), a 404 error may occur. To fix this, do not set links to password-protected pages, and set them to no-index.

(Easy fix: 2/5 severity)

3. Link to a page behind a login

Similar to linking to a password-protected page, if a link points to a page that is only accessible after login and the user is not logged in, a 404 error may occur. To fix this, don't set links to pages behind a login. If you notice users attempting to link to these pages when not logged in, ask them to log in first.

(Don't link private pages: 2/5 severity)

4. Broken internal link

If an internal link on your website points to a page that no longer exists or the link has a typo, a 404 error will occur. To fix this, update the link.

(Fix the link: 2/5 severity)

5. Broken external link

If another website links to a page on your site that doesn't exist, a 404 error will occur. To fix this, contact the owner of the external website and ask them to update the link. It's really smart.

(Monitor and manage your inbound links: 2/5 severity)

6. Page deleted

If a page has been deleted and the URL is not redirected to another page, a 404 error will occur. To fix this, set up a 301 redirect from the deleted page to a relevant live page. One thing about the internet is that it never forgets. It thinks your old page is there until you prove otherwise.

(Decommission pages by setting redirects to relevant pages at the time of making the change: 3/5 severity)

7. URL changed

If the URL of a page changes and the old URL is not redirected (usually as the result of a URL edit - or even sloppy SEO optimization work), a 404 error will occur. To fix this, set up a redirect from the old URL to the new one. This is the 404 error most people experience.

(Actively manage 301/302 redirects: 3/5 severity)

8. Domain name has been changed

If you change the domain, and the old domain is not redirected to the new one, a 404 error will occur likely on all pages except the home page. Your website is basically down. To fix this, set up a domain redirect from the old domain to the new one.

(Proactively manage 301 and 302 redirects: 4/5 severity)

9. Website migration shortcuts

If your website is migrated to a new platform or server and the URLs change without proper redirects, a 404 error will occur. To fix this, ensure that all old URLs are redirected to the new ones during the migration process. This is such a common error, it's near unbelievable it still occurs. And it's entirely preventable.

Inexperienced website owners or rushed developers might attempt to short cut the prospect of 404 errors by redirecting everything to the home page. Doing so only postpones the issues as you begin to create new pages and discover the address can't be used because it's been redirected.

(Proactively manage 301 and 302 redirects: 4/5 severity)

10. Server Misconfiguration

If the server is misconfigured, it may return a 404 error for all pages on the site. Your site is officially down and if there are other websites on the server, they are likely down too. To address this, check your server configuration or contact your webmaster to figure it out.

(Contact your webmaster, hosting provider, or IT department: 5/5 severity)

To set a redirect in HubSpot:

301 or 302 Redirect?

301 is the code for permanent, set this type of redirect if you don't expect it to be used again in the future. 302 is the code for a temporary redirect, set this one if you plan to reuse it in the near future. For the more experienced technical people, you may want to look under the options menu where you can set priority, query strings, and more.

If you're new to redirects or are experiencing a lot of issues with your website, consider purchasing a Technical SEO Audit from our friends at SEO Audits. Don't guess about your SEO, know!