An HTTP status codes cheat sheet allows you to quickly reference codes, understand what is happening on a website’s backend, identify errors that need to be fixed, and identify ways to optimize the site for improved SEO.
We created an HTTP error codes PDF for you to download to help you quickly reference the most important HTTP status codes. In addition to the HTTP status codes cheat sheet, we created a guide to help you identify what each HTTP status code means and which we believe are most relevant to SEO.
- What exactly are HTTP status codes?
- The most frequently used HTTP status codes
- Recognizing HTTP status organization
- Cheatsheet for HTTP status codes
- 1xx Information Request 2xx Status Codes Success Status Codes
- 3xx Redirection Status Codes
- 4xx Client Error 5xx is a status code. Server Error Status Codes
What Exactly Are HTTP Status Codes?
HTTP, or Hypertext Transfer Protocol, is a standard protocol that defines how messages are formatted and transmitted across the internet. HTTP status codes are sets of numbers that describe what is happening between the client (or browser) and the server during the transfer process.
When the codes indicate that a website is not loading properly, they are sometimes referred to as browser error codes or internet error codes.
You don’t need to know every HTTP status code, but there are a few that you should be aware of in order to avoid SEO issues. The following are some of the most common codes:
- When a server is unable to locate a resource or URL, the HTTP status code 404 is returned.
- When a server is unable to process a request due to invalid syntax, HTTP status code 400 is returned.
- HTTP status code 500: When a server is unable to fulfill a request and does not have information on the specific issue.
Our HTTP status codes cheat sheet contains over 60 codes, and our guide explains which codes we believe are most important for SEO and website status.
Understanding HTTP Status Management
Each HTTP status code’s value is not chosen at random. Each code’s first number aids in categorizing the code into a specific situation or problem.
- 1xx Information Request Status Codes
- 2xx Success
- 3xx Status Codes Redirection
- 4xx Status Codes Client Error
- 5xx is a status code. Server Error Status Codes
We’ve compiled these HTTP status code cheat sheets to help you fully understand each code and the specific situation.
Cheat Sheet for HTTP Status Codes
1xx Status Codes: Information Request
- 1xx HTTP status codes indicate that a server is processing data but has not yet completed the request completely. The majority of 1xx status codes are unrelated to SEO situations.
- 100 – Continue: The client request is complete and is being processed.
- 101 – Protocol Switching: The client requested that the protocol type be changed, and the server agreed.
- 102 – Processing: The processing is taking longer than usual.
2xx Success Status Codes
2xx HTTP status codes indicate that a request has been completed and the transfer has occurred as expected. Other than indicating that things are working as they should, 2xx status codes aren’t particularly relevant to SEO.
- 200 – OK: The connection between the client and the server has been established. Everything is in order, and nothing should have an adverse effect on SEO.
- 201 – Created: The client successfully created something (such as a new page) on the server.
- 202 – Accepted: The client requested that something be created on the server. It was accepted, but it has not yet been finished.
- 203 – Non-Authoritative Information: Information was transmitted but not derived from a primary source.
- 204 – No Content: The request was received, but no data was delivered to the client.
- 205 – Reset Content: As with 204, the request was received and no data was sent to the client, but the response includes a request to update the content.
- 206 – Partial Content: The client received only a portion of the header content.
- 207 – Multi-Status: The server passed the results of several independent operations at the same time, which are placed in the message body as an XML document.
Status Codes: 3xx Redirection
3xx HTTP status codes indicate that the client requested information that is no longer available at the specified address. These are frequently referred to as redirect codes, and they are very important to marketers because they affect both visitor experience and SEO performance.
Sending a visitor to a 404-page, for example, is a bad experience if they request content that has moved. You can use redirection to send visitors to relevant content that already exists. Furthermore, it informs search engines about what content is available on your site and how you want them to crawl and index it. Both of these factors have an impact on your long-term SEO results.
3xx SEO-Related Status Codes
- 301 – Permanently Moved: A resource (or URL) request is permanently redirected to another resource. A 301 redirect can be set up for a page that is no longer available. This redirects the client to another live page rather than an error page, and it also informs search engines that the page’s index needs to be updated.
- 302 – Found: Similar to 301, but this is a temporary redirect rather than a permanent redirect. It redirects clients from the old URL to the new one, but it does not instruct search engines to update the page’s index (as a 301 would).
- 307 – Temporary Redirection: A 307 redirection is more specific than a 302 redirection. The server does not see the request, so the browser handles the redirect on its own. When a website is on the HSTS preload list, it is frequently used on HTTPS-served pages.
Other Important Considerations Status Codes 3xx
- 300 – Multiple Choices: Indicates that a resource has been relocated and provides a list of alternatives.
- 303 – See Other: The requested resource is available at a different URL than the one specified.
- 304 – Not Modified: The client requests the resource only if it hasn’t changed since the last document cache.
305 – Use Proxy: Only the proxy specified in the response allows access.
Client Error 4xx Status Codes
4xx HTTP status codes indicate that a client-side problem has occurred. The browser used to access a website is referred to as a “client.” 4xx status errors indicate a problem with the browser’s ability to receive information from the server.
These codes are generally undesirable for SEO because missing pages create a negative experience for visitors. Furthermore, 404 errors indicate that there are pages on your site that aren’t driving traffic or producing SEO results.
4xx SEO-Related Status Codes
- 404 – Not Found: The resource or URL is no longer available, and the server is unable to return any information. 404 errors on a website can have a negative impact on both SEO and user experience. To send requests for a nonexistent page to a live page, all 404 pages should use a 301 redirect.
- 410 – Gone: The resource or URL no longer exists and was deleted intentionally rather than redirected. A 410 indicates to search engines that the page should be removed from the index rather than redirected to a different URL.
Other Crucial 4xx Status Codes
- 400 – Bad Request: A syntax error prevents the request from being processed.
- 401 – Unauthorized: Access to the requested resource requires authorization.
Forbidden: The user is attempting to access a resource that they are not authorized to access.
- 408 – Request Timeout: The relay server’s transmission timeout from the client has expired.
- 410 – Gone: A resource that was previously located on the URL has vanished or is no longer available.
- 429 – Too Many Requests: The client is attempting to send an excessive number of requests in a short period of time.
Additional 4xx Status Codes
- 402 – Payment Is Necessary
- Method 405 – Not Allowed
- 406 – Inadmissible
- 407 – Proxy Authentication Is Necessary
- 409 – Disagreement
- 411 – Required Length
- 412 – Failed Precondition
- 413 – Request Entity Too Large
- 414 – Request-URL Too Long
- 415 – Unsupported Media-Type
- 416 – Requested Range Unsatisfactory
- 417 – Failed Expectation
- Unprocessable Entity 422
- 423 – Secured
- 424 – Abandoned Dependency
- Unordered Collection 425
- 426 – Upgrade Necessary
- 428 – Precondition Necessary
- 431 – Request Header Fields Are Excessively Large
- 444 – No Reaction
- 449 – Try Again With (Microsoft)
- 450 – Restrictions imposed by Windows Parental Controls (Microsoft)
- 451 – Unavailable Due to Legal Issues
Server Error: 5xx Status Codes
The HTTP status code 5xx indicates that something is wrong on the server-side. Although the client made a valid request, the server was unable to complete the transfer. When a server generates 5xx errors, it can have a negative impact on SEO (as it may instruct search engines to deindex a page), so it’s critical to resolve these issues as soon as possible.
5xx SEO-Related Status Codes
- 503 – Service Unavailable: The server is unable to process the request due to a temporary technical issue. The server informs search engines that processing has been halted on purpose. When reading other 5xx errors, the search engine will not change the indexing status. If the 503 error persists for an extended period of time, search engines may begin to interpret it as a permanent error and de-index the page.
Other Significant 5xx Status Codes
- Internal Server Error 500: An error that does not match any of the other class errors.
- 501 – Not Implemented: The server is unable to understand or support the request.
- The server received an invalid message from the upstream server, resulting in a 502 error.
Additional 5xx Status Codes
- Gateway Timeout (504)
- HTTP Version 505 – Not Supported
- Variant 506 Also Negotiates
- 507 – Inadequate Storage
- 509 – The Bandwidth Limit Has Been Exceeded
- 510 – Do Not Extend
- 511 – Network Authentication Is Necessary
- Permission Denied – 550
Download the PDF version of this HTTP Cheat Sheet
Download our HTTP status codes cheat sheet and keep it nearby for quick reference and identification of all status codes to get a list of all 60+ HTTP codes.
Locate and Repair HTTP Errors on Your Website
Use your newfound knowledge of HTTP status codes to help improve your website. To make your website more appealing to both search engines and users, use an HTTP status checker to find and fix HTTP errors.