This code indicates a properly functioning page. Yay – success!
301 Permanent Redirect
If you want to redirect bots and visitors, who land on page A to go to page B, you need to use 301 permanent redirect. Frequently used to redirect an old domain to a new one or to redirect whole domains from http to https. About 85% of the linking juice1 that is originally sent to Page A is moved to Page B.
Server-side 301 redirects can be configured in the .htaccess file, located in the website’s public_html folder.
302 Temporary Redirect
You can use 302 redirect if you want bots and visitors who land on Page A to go to Page B temporarily. None of the linking juice2 that is originally sent to Page A will be passed to Page B. 302 redirects are not to be used as permanent solutions.
There are times when using 302 redirect is appropriate: 1) A/B testing of a webpage; 2) Getting client feedback on a new page; 3) Fixing a broken webpage.
400 BAD REQUEST
The request to visit the website was corrupted, & the application you are using (e.g., your web browser) accessed it incorrectly. It could also be caused by a bad internet connection or a caching issue.
You should: 1) Check your internet connection and settings; 2) Clear your cache; 3) Try a different browser.
You are not authorized to access the page you are trying to visit. A login was presented, but you didn’t log in properly.
To access this web page, you need to obtain a password. Contact the web page administrator or owner.
You are not allowed to visit the page you requested. You were trying to access a directory or page that you don’t have access to, and there was no login presented.
To access the web page, you need to obtain an account or a login. Try going back to the home page and checking if you can sign-up for an account.
404 NOT FOUND
You are trying to access a web page that doesn’t exist. You get the 404 error whenever you 1) mistype the URL; 2) Try to access a deleted or a moved page; or 3) Access a page with a broken link.
Set-up custom 404 pages with instructions for the visitors where they should go next (i.e., Home Page). Double-check the URL spelling, punctuation, and suffix (.com, .net, .org, etc.) of the domain name.
405 METHOD NOT ALLOWED
The server is refusing to perform your request. The web browser placed a request for the web page, but the server is refusing to fulfill it.
If it is an error in the web site's code or a faulty redirect, it has to be fixed on the back-end. However, you can always check: 1) The spelling of the requested URL; 2) Rollback recent upgrades to the site; 3) Uninstall new extensions, plugins; 4) Check the .htaccess file in your public_html directory.
408 REQUEST TIMEOUT
The request to retrieve the page was stopped before the server finished fetching page information, which can happen if you 1) closed the browser too quickly; 2) clicked on a link too soon, or 3) hit a stop button in the browser.
Try to reload and access the page again.
You are trying to access a web page that doesn’t exist. The page is no longer available from the server, and there is no forwarding information available.
Remove any references or links on your website to ghost pages; otherwise, you are sending visitors to dead ends.
451 UNAVAILABLE FOR LEGAL REASONS
You requested a page that can’t be displayed because it has been censored by the government. The court orders block the site. It can mean that the page has copyright issues or illegal political content.
You can first try accessing the page by using the HTTPS protocol instead of HTTP. If the website is blocked due to censorship, you can try accessing it through Private Internet Access (PIA).3
500 INTERNAL SERVER ERROR
A web server encounters some form of an internal error. When the webserver is overloaded, it is not able to handle requests properly.
You should try to: 1) Reload the page; 2) Clear your cache; 3) Delete cookies; 4) Restart or try a different browser.
501 NOT IMPLEMENTED
You requested a page with a feature that your browser does not support. The server doesn’t have the functionality to fulfill your request. Error 501 can sometimes be caused by malware.
You should try to: 1) Reload the page; 2) Clear your browser cache; 3) Check your VPN and/or proxy4; 4) Contact your host provider.
502 BAD GATEWAY
While acting as a gateway or a proxy, the server received an invalid response from the upstream server. The response received is bad, overloaded, or it has network issues.
It is a webserver error. You can try: 1) Reloading the page; 2) Using the browser in Safe Mode5; 3) Checking for server connectivity issues; 4) Contacting your host.
503 SERVICE UNAVAILABLE
You are trying to access a web page where the server is down or the site is busy. The server may be undergoing maintenance or is overloaded with requests.
You should try reloading and accessing the web page later.
504 GATEWAY TIMEOUT
There is a server to server communication problem. A web server attempting to load a page did not get a timely response from the server where the page is hosted.
You can try: 1) Reloading the page; 2) Disabling proxy settings; 3) Checking your DNS; 4) Temporarily disabling CDN6; 5) Checking with your host; 6) Rolling back recent upgrades to the site.
BONUS: 418 I’M A TEAPOT
The server refused to brew coffee because it is, permanently, a teapot, and the resulting entity-body MAY be short and stout. (☉_ ☉) Error code 418 was released on April’s Fool Day in 1998 as part of the Request for Comments (RFC)7. Who said developers don’t have a sense of humor. <(￣︶￣)>
Don’t brew coffee in a teapot. Try a coffeemaker instead. (~˘▾˘)~
Fixes You Can Always Try
Based on fixes for most errors, there are few things you can always try:
❄ Check the spelling of your URL;
❄ Reload the page;
❄ Clear your cache;
❄ Try a different browser;
❄ Try accessing the page in a Safe Mode;
❄ Check your internet connection;
❄ Rollback recent upgrades to the site;
❄ Check your .htaccess file in your public_html directory;
❄ Contact your host provider.