What is an HTTP Status Code?

1XX: Informational

Informational Status Codes:

100 → Continue
101 → Switching Protocols
102 → Processing Request
103 → Early Hints

2XX: Successful

Successful Status Codes:

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 → IM Used

3XX: Redirection

300 → Multiple Choices
301 → Moved Permanently
302 → Found
303 → See Other
304 → Not Modified
305 → Use Proxy
306 → Switch Proxy
307 → Temporary Redirect
308 → Permanent Redirect

4XX: Client Error

We web developers hate this (most of the time)!

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 → Payload Too Large
414 → URI Too Long
415 → Unsupported Media Type
416 → Range Not Satisfiable
417 → Expectation Failed
418 → I'm a Teapot
421 → Misdirected Request
422 → Unprocessable Entity
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
510 → Not Extended
511 → Network Authentication Required

As a web developer, you really don't need to memorize all of these.

In most scenarios, you'll only see a handful of codes such as 200, 301, and 404.

Just bookmark this page and come back whenever you need to, and take a glance.