science

List of HTTP status codes

List of HTTP status codes is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of HTTP status codes rather than just read about it. In short: This article lists standard and notable non-standard HTTP response status codes. Standardized codes are defined by IETF as documented in Request for Comments (RFC) publications and maintained by the IANA.

Key takeaways

List of HTTP status codes belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of HTTP status codes to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of HTTP status codes from memory before moving on to harder problems.

Reference excerpt

This article lists standard and notable non-standard HTTP response status codes. Standardized codes are defined by IETF as documented in Request for Comments (RFC) publications and maintained by the IANA. Other, non-standard values are used by various servers. The descriptive text after the numeric code – the reason phrase – is shown here with typical value, but in practice, can be different or omitted.

Standard codes Status codes defined by IETF are listed below. Emphasized terms must, must not and should are interpretation guidelines as given by RFC 2119.

1xx informational response An informational response indicates that the request was received and understood and is being processed. It alerts the client to wait for a final response. The message does not contain a body. As the HTTP/1.0 standard did not define any 1xx status codes, servers must not send a 1xx response to an HTTP/1.0 compliant client except under experimental conditions.

100 Continue The server has received the request headers and the client should proceed to send the request body (in the case of a request for which a body needs to be sent, such as a POST request). Sending a large request body to a server after a request has been rejected for inappropriate headers would be inefficient. To have a server check the request's headers, a client must send Expect: 100-continue as a header in its initial request and receive a 100 Continue status code in response before sending the body. If the client receives an error code such as 403 (Forbidden) or 405 (Method Not Allowed) then it should not send the request's body. The response 417 Expectation Failed indicates that the request should be repeated without the Expect header as it indicates that the server does not support expectations (this is the case, for example, of HTTP/1.0 servers). 101 Switching Protocols The requester has asked the server to switch protocols and the server has agreed to do so. 102 Processing (WebDAV; RFC 2518) A WebDAV request may contain many sub-requests involving file operations, requiring a long time to complete the request. This code indicates that the server has received and is processing the request, but no response is available yet. This prevents the client from timing out and assuming the request was lost. The status code is deprecated. 103 Early Hints (RFC 8297) Used to return some response headers before final HTTP message.

2xx success A success status indicates that the action requested by the client was received, understood, and accepted.

200 OK Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request, the response will contain an entity describing or containing the result of the action. 201 Created The request has been fulfilled, resulting in the creation of a new resource. 202 Accepted The request has been accepted for processing, but the processing has not been completed. The request might or might not be eventually acted upon, and may be disallowed when processing occurs. 203 Non-Authoritative Information (since HTTP/1.1) The server is a transforming proxy (e.g. a Web accelerator) that received a 200 OK from its origin, but is returning a modified version of the origin's response. 204 No Content The server successfully processed the request, and is not returning any content. 205 Reset Content The server successfully processed the request, asks that the requester reset its document view, and is not returning any content. 206 Partial Content The server is delivering only part of the resource (byte serving) due to a range header sent by the client. The range header is used by HTTP clients to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams. 207 Multi-Status (WebDAV; RFC 4918) The message body that follows is by default an XML message and can contain a number of separate response codes, depending on how many sub-requests were made. 208 Already Reported (WebDAV; RFC 5842) The members of a DAV binding have already been enumerated in a preceding part of the (multistatus) response, and are not being included again. 226 IM Used (RFC 3229) The server has fulfilled a request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.

3xx redirection A 3xx status indicates that the client must take additional action, generally URL redirection, to complete the request. A user agent may carry out the additional action with no user interaction if the method used in the additional request is GET or HEAD. A user agent should prevent cyclical redirects.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with List of HTTP status codes

Start with the simplest possible case. Write down what List of HTTP status codes claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of HTTP status codes before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of HTTP status codes ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of HTTP status codes

In research: List of HTTP status codes appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of HTTP status codes in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of HTTP status codes is common in secondary-school and first-year university syllabi. It links to neighbouring topics Hypertext Transfer Protocol status codes, Internet-related lists, so understanding it makes those chapters shorter.
In everyday life: Look for List of HTTP status codes outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study List of HTTP status codes in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of HTTP status codes means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of HTTP status codes out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of HTTP status codes in simple terms?

Why does List of HTTP status codes matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of HTTP status codes?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of HTTP status codes.