4XX Client Error HTTP Codes

400 Bad Request

The 400 Bad Request response status code indicates that the server is unable or refuses to process the request due to a client error. Various causes that may trigger this error are URL String syntax error, corrupted browser cache & cookies, DNS lookup cache, too large file size, or a generic server error.

400 Bad Request Solutions:

  1. Checking if the submitted URL has been typed correctly. Make sure they’re separated by forwarding slashes as well. If the URL includes special characters, double-check that they’ve been encoded properly and are valid URL characters.
  2. Clear browser cache. If any locally saved website files are corrupted, instead of the expected website content, a 400 Bad Request error will be issued.
  3. Clear browser cookies. If clearing the cache in your browser didn’t work, it’s time to clear the cookies as well. Hundreds of distinct cookies might be used by a single website. It’s possible that just one of them has expired or become corrupted, resulting in a 400 Bad Request.
  4. Check if file upload exceeds the server limit. A 400 Bad Request error will appear if you try to upload a file to a website that is larger than the server’s file size limit.
  5. Clearing DNS cache.  Another common cause of a 400 Bad Request is when local DNS lookup data becomes either corrupted or out-of-date.
  6. Disabling browser extensions.

401 Unauthorized

A 401 response status code indicates that the request sent by the client could not be authorized because there are no valid authentication credentials set up.

Suggested 401 Unauthorized Solutions

  1. Checking the submitted URL.
  2. Cleaning firewall and browser cache.
  3. Logging out and logging in again.
  4. Disabling plugins or extensions.
  5. Clearing DNS records.
  6. Reloading the page.
  7. Contacting the hosting provider.

403 Forbidden

This response status code means that you don’t have permission to access the resource. It occurs when the web server understands the request but can’t provide you with additional access. This can also be fixed using the same suggested solutions for the 401 response status code.

404 Errors (Broken Links)

A 404 not found error is an HTTP status code that indicates that the page you requested was not located on the website’s server. This error can be fixed on the developer side by simply redirecting the link to the correct link and deleting the restored pages.

This error is actually very important to fix for SEO…if you have a lot of them.

If there are one or 2 here and there, that isn’t going to kill your organic rankings, but if you are linking to dozens or hundreds of 404’s, Google will think you are not a very responsible website and penalize or filter you.

Some 404 errors matter a lot more than others.  For example, one of the most common issues with 404 errors come after a website redesign.  The web design team doesn’t know SEO (even if they claim to know it).  They change the URLs on your website without setting up 301 redirects…and a few months later your rankings have tanked.

What has happened here is there are pages on your website with links going to them that are helping you rank.  Now those pages 404 and the SEO power or “link juice” that you were receiving goes “poof.”

404 Error Code Solution

Setup 301 redirects from old URLs to new URLs

410 Gone

The 410 Gone Error is an HTTP response status code that indicates that the client’s requested resource has been permanently deleted and that no other redirection or forwarding address should be expected.

Suggestion 410 Gone Error Code Solutions

  1. Disabling your site’s plugin(s).  Many WordPress plugins might cause HTTP error 410 codes to appear on your site. They’re usually plugins that change the URL structure of your page or allow you to set up redirects. 410 errors, on the other hand, can be caused by more prevalent compatibility difficulties. Disabling all plugins at once is the best strategy to rule out plugins as the source of the error. However, to be cautious, you should make a backup of your website first.
  2. Repair your website’s .htaccess file. The.htaccess file in your WordPress installation allows you to configure server settings such as redirection, access restrictions, and more. If you’ve ever made changes to your .htaccess file, it’s possible that you’ve accidentally caused a 410 error on your website. Connecting to your website’s server through File Transfer Protocol is the simplest approach to open your .htaccess file (FTP).
  3. Re-installing your WordPress Core Files. If the first two steps fail, there could be a problem with your WordPress core files. These files allow WordPress to function. They can also become corrupted in some circumstances because of poor configuration or unauthorized alterations.
  4. Repair essential files. WordPress has a function that allows you to reinstall the most recent version of the Content Management System (CMS). It should have no effect on the functionality or content of your site, but maintaining a recent backup is always a good idea.

411 Length Required

The server refuses to accept the request because the Content-Length header wasn’t defined in your request.

429 Too Many Requests

The HTTP 429 Too Many Requests response status code indicates that the user has sent an excessive number of requests in a short period of time (“rate limiting”). This response may include a Retry-After header that specifies how long to wait before making another request.

Suggested 429 Error Code Solutions

  1. Wait to send another request. Waiting to send another request is the simplest technique to fix an HTTP 429 error. This status code is frequently accompanied by a “Retry-after” header, which indicates how long you should wait before sending another request. It usually takes a few seconds or minutes.
  2. Implement an exponential backoff. This is very useful if you don’t know how long to wait before attempting again since a “Retry-after” header isn’t sent. Your application will not instantly repeat a failed request if you use this method; instead, it will execute a series of retries with extended wait durations between each attempt. With this, you’ll know what wait time or rate is appropriate after the request is eventually granted.

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