Sep 25, 2024 3 minute read
HTTP Status Codes
Table of Contents
- What are HTTP Status Codes?
- The Structure of HTTP Status Codes
- List of HTTP Status Codes
- Useful Links
When you're browsing the web, a lot is happening behind the scenes. One of the essential components of this process is HTTP status codes. These codes are like short messages from the server that tell your browser what is happening with your request.
What are HTTP Status Codes?
HTTP status codes are part of the response a server sends back to a client's request. They are three-digit numbers that indicate whether a specific HTTP request has been successfully completed. For example, when you type a URL into your browser and hit enter, the server returns a status code to tell your browser if the request was successful, if there is an error, or if something else is happening.
The Structure of HTTP Status Codes
HTTP status codes are categorized into five classes, each serving a different purpose. Here's a quick overview:
- 1xx: Informational Indicates that the request has been received and is being processed.
- 2xx: Success Confirms that the request was successfully received, understood, and accepted.
- 3xx: Redirection Informs the client that further action is needed to complete the request.
- 4xx: Client Error Indicates an error caused by the client, such as a bad request or unauthorized access.
- 5xx: Server Error Signals that the server failed to fulfill a valid request.
For example, let's use 403 Forbidden:
The first digit (4) indicates a client error, meaning the issue is caused by something from the user's side, like invalid credentials or improper access permissions. Specifically, 403 means that the server understands the request, but refuses to authorize it. This can happen when the user doesn't have the necessary permissions to access the requested resource.
Meanwhile, 401 Unauthorized also shows a client error. However, in this case, the second and third digits tell us that the server is requesting authentication and won’t proceed without valid login credentials.
List of HTTP Status Codes
| Status Code | Function |
|---|---|
| 1XX — Informational | |
| 100 | Continue |
| 101 | Switching Protocols |
| 102 | Processing |
| 103 | Early Hints |
| 2XX — Success | |
| 200 | OK |
| 201 | Created |
| 202 | Accepted |
| 203 | Non-Authoritative Information |
| 204 | No Content |
| 205 | Reset Content |
| 206 | Partial Content |
| 207 | Multi-Status |
| 208 | Already Reported |
| 226 | I'm Used |
| 3XX — Redirection | |
| 300 | Multiple Choices |
| 301 | Moved Permanently |
| 302 | Found |
| 303 | See Other |
| 304 | Not Modified |
| 307 | Temporary Redirect |
| 308 | Permanent Redirect |
| 4XX — Client Error | |
| 400 | Bad Request |
| 401 | Unauthorized |
| 402 | Payment Required |
| 403 | Forbidden |
| 404 | Not Found |
| 405 | Method Not Allowed |
| 406 | Not Acceptable |
| 407 | Proxy Authentication Required |
| 408 | Request Timeout |
| 409 | Conflict |
| 410 | Gone |
| 411 | Length Required |
| 412 | Precondition Failed |
| 413 | Content Too Large |
| 414 | URI Too Long |
| 415 | Unsupported Media Type |
| 416 | Range Not Satisfiable |
| 417 | Expectation Failed |
| 421 | Misdirected Request |
| 422 | Unprocessable Content |
| 423 | Locked |
| 424 | Failed Dependency |
| 425 | Too Early |
| 426 | Upgrade Required |
| 428 | Precondition Required |
| 429 | Too Many Requests |
| 431 | Request Header Fields Too Large |
| 451 | Unavailable for Legal Reasons |
| 5XX — Server Error | |
| 500 | Internal Server Error |
| 501 | Not Implemented |
| 502 | Bad Gateway |
| 503 | Service Unavailable |
| 504 | Gateway Timeout |
| 505 | HTTP Version Not Supported |
| 506 | Variant Also Negotiates |
| 507 | Insufficient Storage |
| 508 | Loop Detected |
| 511 | Network Authentication Required |