403 Forbidden vs 401 Unauthorized HTTP responses

Question

For a web page that exists, but for which a user does not have sufficient privileges (they are not logged in or do not belong to the proper user group), what is the proper HTTP response to serve?

401 Unauthorized?
403 Forbidden?
Something else?

What I've read on each so far isn't very clear on the difference between the two. What use cases are appropriate for each response?

Solution 1

A clear explanation from Daniel Irvine:

There's a problem with 401 Unauthorized, the HTTP status code for authentication errors. And that’s just it: it’s for authentication, not authorization. Receiving a 401 response is the server telling you, “you aren’t authenticated–either not authenticated at all or authenticated incorrectly–but please reauthenticate and try again.” To help you out, it will always include a WWW-Authenticate header that describes how to authenticate.

This is a response generally returned by your web server, not your web application.

It’s also something very temporary; the server is asking you to try again.

So, for authorization I use the 403 Forbidden response. It’s permanent, it’s tied to my application logic, and it’s a more concrete response than a 401.

Receiving a 403 response is the server telling you, “I’m sorry. I know who you are–I believe who you say you are–but you just don’t have permission to access this resource. Maybe if you ask the system administrator nicely, you’ll get permission. But please don’t bother me again until your predicament changes.”

In summary, a 401 Unauthorized response should be used for missing or bad authentication, and a 403 Forbidden response should be used afterwards, when the user is authenticated but isn’t authorized to perform the requested operation on the given resource.

Another nice pictorial format of how http status codes should be used.

Solution 2

Edit: RFC2616 is obsolete, see RFC7231 and RFC7235.

401 Unauthorized:

If the request already included Authorization credentials, then the 401 response indicates that authorization has been refused for those credentials.

403 Forbidden:

The server understood the request, but is refusing to fulfill it.

From your use case, it appears that the user is not authenticated. I would return 401.

---

Solution 3

Something the other answers are missing is that it must be understood that Authentication and Authorization in the context of RFC 2616 refers ONLY to the HTTP Authentication protocol of RFC 2617. Authentication by schemes outside of RFC2617 is not supported in HTTP status codes and are not considered when deciding whether to use 401 or 403.

Brief and Terse

Unauthorized indicates that the client is not RFC2617 authenticated and the server is initiating the authentication process. Forbidden indicates either that the client is RFC2617 authenticated and does not have authorization or that the server does not support RFC2617 for the requested resource.

Meaning if you have your own roll-your-own login process and never use HTTP Authentication, 403 is always the proper response and 401 should never be used.

Detailed and In-Depth

From RFC2616

10.4.2 401 Unauthorized

The request requires user authentication. The response MUST include a WWW-Authenticate header field (section 14.47) containing a challenge applicable to the requested resource. The client MAY repeat the request with a suitable Authorization header field (section 14.8).

and

10.4.4 403 Forbidden The server understood the request but is refusing to fulfil it. Authorization will not help and the request SHOULD NOT be repeated.

The first thing to keep in mind is that "Authentication" and "Authorization" in the context of this document refer specifically to the HTTP Authentication protocols from RFC 2617. They do not refer to any roll-your-own authentication protocols you may have created using login pages, etc. I will use "login" to refer to authentication and authorization by methods other than RFC2617

So the real difference is not what the problem is or even if there is a solution. The difference is what the server expects the client to do next.

401 indicates that the resource can not be provided, but the server is REQUESTING that the client log in through HTTP Authentication and has sent reply headers to initiate the process. Possibly there are authorizations that will permit access to the resource, possibly there are not, but let's give it a try and see what happens.

403 indicates that the resource can not be provided and there is, for the current user, no way to solve this through RFC2617 and no point in trying. This may be because it is known that no level of authentication is sufficient (for instance because of an IP blacklist), but it may be because the user is already authenticated and does not have authority. The RFC2617 model is one-user, one-credentials so the case where the user may have a second set of credentials that could be authorized may be ignored. It neither suggests nor implies that some sort of login page or other non-RFC2617 authentication protocol may or may not help - that is outside the RFC2616 standards and definition.

---

Edit: RFC2616 is obsolete, see RFC7231 and RFC7235.

Solution 4

  +-----------------------
  | RESOURCE EXISTS ? (if private it is often checked AFTER auth check)
  +-----------------------
    |       |
 NO |       v YES
    v      +-----------------------
   404     | IS LOGGED-IN ? (authenticated, aka user session)
   or      +-----------------------
   401        |              |
   403     NO |              | YES
   3xx        v              v
              401            +-----------------------
       (404 no reveal)       | CAN ACCESS RESOURCE ? (permission, authorized, ...)
              or             +-----------------------
             redirect          |            |
             to login       NO |            | YES
                               |            |
                               v            v
                               403          OK 200, redirect, ...
                      (or 404: no reveal)
                      (or 404: resource does not exist if private)
                      (or 3xx: redirection)

Checks are usually done in this order:

• 404 if resource is public and does not exist or 3xx redirection
• OTHERWISE:
• 401 if not logged-in or session expired
• 403 if user does not have permission to access resource (file, json, ...)
• 404 if resource does not exist or not willing to reveal anything, or 3xx redirection

UNAUTHORIZED: Status code (401) indicating that the request requires authentication, usually this means user needs to be logged-in (session). User/agent unknown by the server. Can repeat with other credentials. NOTE: This is confusing as this should have been named 'unauthenticated' instead of 'unauthorized'. This can also happen after login if session expired. Special case: Can be used instead of 404 to avoid revealing presence or non-presence of resource (credits @gingerCodeNinja)

FORBIDDEN: Status code (403) indicating the server understood the request but refused to fulfill it. User/agent known by the server but has insufficient credentials. Repeating request will not work, unless credentials changed, which is very unlikely in a short time span. Special case: Can be used instead of 404 to avoid revealing presence or non-presence of resource (credits @gingerCodeNinja) in the case that revealing the presence of the resource exposes sensitive data or gives an attacker useful information.

NOT FOUND: Status code (404) indicating that the requested resource is not available. User/agent known but server will not reveal anything about the resource, does as if it does not exist. Repeating will not work. This is a special use of 404 (github does it for example).

As mentioned by @ChrisH there are a few options for redirection 3xx (301, 302, 303, 307 or not redirecting at all and using a 401):

• Difference between HTTP redirect codes
• How long do browsers cache HTTP 301s?
• What is correct HTTP status code when redirecting to a login page?
• What's the difference between a 302 and a 307 redirect?

Solution 5

According to RFC 2616 (HTTP/1.1) 403 is sent when:

The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated. If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it SHOULD describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead

In other words, if the client CAN get access to the resource by authenticating, 401 should be sent.

View more solutions

Comments

[Christophe Roussy]

401 'Unauthorized' should be 401 'Unauthenticated', problem solved !

[neurite]

I don't remember how many times me and my colleagues have come back to stackoverflow for this question. Maybe HTTP standards should consider modifying the names or descriptions for 401 and 403.

[Sandeep Anand]

In fact, I am getting a different version of this error. like "os_authType was 'any' and an invalid cookie was sent". So unable to figure out how to solve that. Googled a lot of time , got reasons but didn't get a solution.

[fishbone]

@Qwerty no, the new RFC7231 obsoletes RFC2616. 403 has a different meaning now.

[Barkermn01]

@fishbone you also did not note that status code 401 has been removed from that RFC :D

[Barkermn01]

@fishbone it's been added back to that proposal now but uses a different RFC now 7235 tools.ietf.org/html/rfc7235#section-3.1

[Jean-François Beauchef]

@ChristopheRoussy where it gets confusing is that 403 should be Unauthorized! ;)

[Stijn de Witt]

If that proposal makes any significant changes to the meaning of 401 and 403 then it does not stand a chance. The only thing they need to do is change the name and documentation and it will be hard enough to get all servers to use the new name. We tried obsoleting web standards before and it does not work. The web is too big and moves too slow.

[Stijn de Witt]

403 can remain 'Forbidden'. That name is clear enough. It's 401 which is confusing and should probably just be described as 'Not logged in'

[VirtuosiMedia]

And if it's not clear if they can access or not? Say that I have 3 user levels - Public, Members, and Premium Members. Assume that the page is for Premium Members only. A public user is basically unauthenticated and could be in either Members or Premium Members when they log in. For the Member user level, a 403 would seem appropriate. For Premium Members, the 401. However, what do you serve the Public?

[VirtuosiMedia]

Thanks, that helped clarify it for me. I'm using both - the 401 for unauthenticated users, the 403 for authenticated users with insufficient permissions.

[Ben Challenor]

The default IIS 403 message is "This is a generic 403 error and means the authenticated user is not authorized to view the page", which would seem to agree.

[Mel]

imho, this is the most accurate answer. it depends on the application but generally, if an authenticated user doesn't have sufficient rights on a resource, you might want to provide a way to change credentials or send a 401. I think 403 is best suited for content that is never served. In asp.net this would mean web.config files *.resx files etc. because no matter which user logs in, these files will NEVER be served so there is no point in trying again.

[Mel]

I didn't downvote but I find this answer quite misleading. 403 forbidden is more appropriately used in content that will never be served (like .config files in asp.net). its either that or a 404. imho, it wouldn't be appropriate to return 403 for something that can be accessed but you just didn't have the right credentials. my solution would be to give an access denied message with a way to change credentials. that or a 401.

[Brilliand]

"The response MUST include a WWW-Authenticate header field (section 14.47) containing a challenge applicable to the requested resource." It would seem that if you don't want to use HTTP-style authentication, a 401 response code is not appropriate.

[Brilliand]

Relevant question: stackoverflow.com/questions/1748374/…

[p.matsinopoulos]

@JPReddy Your answer is correct. However, I would expect that 401 to be named "Unauthenticated" and 403 to be named "Unauthorized". It is very confusing that 401, which has to do with Authentication, has the format accompanying text "Unauthorized"....Unless I am not good in English (which is quite a possibility).

[Zaid Masud]

@p.matsinopoulos your interpretation of authorized vs authenticated is correct, it is in fact more accurate to call 401 Unauthenticated

[JPReddy]

Sorry to say that '401 Unauthorized' is not named by me its the protocol which named it: w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.2

[Davide R.]

@ZaidMasud, according to RFC this interpretation is not correct. Cumbayah's answer got it right. 401 means "you're missing the right authorization". It implies "if you want you might try to authenticate yourself". So both a client who didn't authenticate itself correctly and a properly authenticated client missing the authorization will get a 401. 403 means "I won't answer to this, whoever you are". RFC states clearly thath "authorization will not help" in the case of 403.

[Davide R.]

This is not correct. Refer to RFC and to @Cumbayah's answer.

[Zaid Masud]

@DavideR. the RFC uses authentication and authorization interchangeably. I believe it makes more sense when read with the authentication meaning.

[ldrut]

I'll back Billiand here. The statement is "If the request already included Authorization credentials". That means if this is a response from a request which provided the credential (e.g. the response from a RFC2617 Authentication attempt). It is essentially to allow the server to say, "Bad account/password pair, try again". In the posed question, the user is presumably authenticated but not authorized. 401 is never the appropriate response for those circumstances.

[Shahriyar Imanov]

401 is Authentication error, 403 is Authorization error. Simple as that.

[Juan Pablo Rinaldi]

Brilliand is right, 401 is only appropriate for HTTP Authentication.

[Kyle]

You left out "Well that’s my view on it anyway :)" when copying from his blog post and unfortunately his view is wrong. As others have stated 403 means that you can't access the resource regardless of who you are authenticated as. I typically use this status code for resources that are locked down by IP address ranges or files in my webroot that I don't want direct access to (i.e. a script must serve them).

[Guillermo Gutiérrez]

I think 403 is a way to say "I have the resource, but I will ignore your request".

[CurtainDog]

+1, but an uncertain +1. The logical conclusion is that a 403 should never be returned as either 401 or 404 would be a strictly better response.

[jperelli]

"401 Unauthorized [...] is not for authorization" seems overwhelmingly contradictory.

[BozoJoe]

This answer is reversed. Unauthorized is not the same as Un-authenticated. @DavideR is right. Authentication and Authorization are NOT interchangeable

[Zaid Masud]

@DavideR. please believe me you are getting this wrong. When the RFC states for 403 that "authorization will not help" it's referring to the 401 authorization, which semantically means authentication. A client who is authenticated should never see 401, which is exactly how the RFC defines 401: "The request requires user authentication."

[André Caron]

I would add that the 403 status code description includes "Authorization will not help and the request SHOULD NOT be repeated.". My understanding is that it is not a question of having permissions.

[jhorback]

I agree that this interpretation is not correct. 403 was created to deny directory access not for authorization. I know as developers, 403 "feels" correct when denying authorization, however, it clearly states in the RFC what the other down voters have stated. See: w3.org/Protocols/rfc2616/rfc2616-sec10.html - The URL that returns a 403 will never allow access no matter what the authentication credentials are changed to.

[marcovtwout]

So what should we do when the user requests a page that requires non-http authentication? Send status code 403?

[Ruan Mendes]

@Mel I think a file that should not be accessed by the client should be a 404. It's a file that is internal to the system; the outside should not even know it exists. By returning a 403 you are letting the client know it exists, no need to give that information away to hackers. The spec for 403 says An origin server that wishes to "hide" the current existence of a forbidden target resource MAY instead respond with a status code of 404 (Not Found).

[Wowbagger and his liquid lunch]

Code 401 is missing for some reason in the latest RFC draft: tools.ietf.org/html/rfc7231#page-58 <scratches head>

[ggg]

This is important: "if you have your own roll-your-own login process and never use HTTP Authentication, 403 is always the proper response and 401 should never be used."

[pashute]

This answer is simply wrong! Read answer #13 here below, and the RFC. It is clearly stated that for both authentication and authorization the 401 Not Authorized should be used, with different information in the body. Also wrong is the answer to use 401 at all in this case which is not using HTTP authentication. In that case you should choose 403 or Access Denied as clarified in the answers below and their well documented sources.

[Alex]

@marcovtwout Send a 302 to your login-page, or a 403 containing a body with information how to log in?

[Alex]

RFC2616 should be burned and replaced by RFC7235, but contains no changes in this topic as far as I can see.

[Brian]

This is interesting. Based on RFC 7231 and RFC 7235, I don't see an obvious distinction between 401 and 403

[Dave Watts]

The use of a 404 has been mentioned in previous answers. You're on point re: information leakage and this should be an important consideration for anyone rolling their own authentication/authorization scheme. +1 for mentioning OWASP.

[Admin]

I agree with this answer wholeheartedly; the distinction between any authorization and RFC2617 authorization is critical. I do find it irritating that the HTTP spec doesn't provide any mechanism for more general authentication methods.

[Søren Boisen]

-1, see Idruts answer. 401 is meant to be used solely with HTTP authentication as the RFC states that the WWW-Authenticate header MUST be sent in the response.

[BaltoStar]

-1 Daniel Irvine is wrong about this and so are the 900+ up-voters who didn't bother to read the RFC carefully. 401 is unauthorized for any reason : either due to credentials missing or failed authentication OR because account is not authorized to access resource. 403 is locked-down resource - for example, a request for partner resources that validates partner id against client ip ( for the scenario where requests submitted by each partner is known to originate from specific client ip )

[Tom Lint]

To all downvoters referring to an RFC (most likely 2616), you are all wrong. As specified in the answer by @Idrut, "Forbidden means that the client has authenticated successfully, but is not authorized.". He references RFC7231 and RFC7235 which obsolete RFC 2616.

[Rob]

@Mel You say the answer is misleading (it is), but only enforce the answer, rather than contradict it. Both the answer and your comment recommend using 401 and not using 403.

[Michael Blackburn]

I Agree with this answer. 401 is "I don't know who you are" and 403 is "I know who you are, but you can't access this file." I believe the RFC backs this, but clearly there's room for debate. So forget what the RFC says. Isn't one of the precepts of security that you don't betray information you don't need to? i.e. if a user submits an incorrect password, you don't reply "well, you got the username right, so just try brute-forcing the password." Replying '403' to a locked-down-will-never-be-served file is essentially the same thing. "I'll never serve sooper-sekrit.htm by HTTP, try FTP!"

[Michael Blackburn]

2616 should be burned. Several newer RFCs are much clearer that there is a need to differentiate between "I don't know you" and "I know you but you can't access this." There is no legitimate reason to acknowledge the existence of a resource that will never be fulfilled (or not fulfilled via http), which is what the 403-truthers are suggesting.

[Michael Blackburn]

403 means "I know you but you can't see this resource." There's no reason for confusion.

[jchook]

Doesn't RFC7235 provide for "roll-your-own" or alternate auth challenges? Why can't my app's login flow present its challenge in the form of a WWW-Authenticate header? Even if a browser doesn't support it, my React app can...

[Eugen Konkov]

This is not accurate answer. It does not cover what to deal with this requirement in case of 401: The response MUST include a WWW-Authenticate header field

[mmlac]

I think the 401 RFC definition is just plain outdated. It imho should be 401 is Unauthorized, you need to somehow get an auth token, depending on what the server accepts. IF the server sends a WWW-Authenticate, you may use that. In reality, i.e. OAuth Bearer token cannot be created by those means but it is indeed an unauthenticated request that needs to submit a Authentication header. Personally I send 401 for any kind of unauthenticated request, as we are in an age post what the RFC considers as authentication. 403 is definitively wrong for i.e. missing OAuth token, 400 is too generic

[VIGNESH]

The draft was approved and is now RFC 7231.

[Mark Amery]

While this seems to me like it's probably an accurate interpretation of the old RFC 2616, note that RFC 7231 defines the semantics of a 403 differently, and in fact explicitly states that "The client MAY repeat the request with new or different credentials." So while this answer was accurate in 2010, it's completely wrong today, because the meaning of the status code has been rewritten beneath our feet. (Annoyingly, the Changes from RFC 2616 appendix doesn't acknowledge the change!)

[xdumaine]

Googlers beware: This answer references RFC-2616 which was later made obsolete by a RFC 7231.

[xdumaine]

I want to Echo @TomLint here that Googlers beware: Many of the comments here stating this is wrong reference RFC-2616 which was later made obsolete by a RFC 7231. The answer is correct.

[arcuri82]

"If the request included authentication credentials, then the 401 response indicates that authorization has been refused for those credentials. The client MAY repeat the request with a new or replaced Authorization header field (Section 4.1)." However, then "4.2. The 'Authorization' header field allows a user agent to authenticate itself with an origin server". Looks like in RFC7235 they use the term "authorization" like it was "authentication". In that case, it might seem that an authenticated but not authorized user should not get a 401, but rather 403

[Mark Amery]

-1; these passages have already been quoted in other answers here, and yours adds nothing new. I'd argue that it's patently not clear what the distinction is; you summarise the two codes as "lacks valid authentication" and "refuses to authorise" but I cannot conceive of any situation in which one of those short descriptions would apply where the other could not be interpreted to apply as well.

[cjbarth]

There are many answers here that cover many RFC's and are edited and updated muddying the waters. I included a link to explain what authenticated is and what authorized is and left off all outdated RFC's so that the application is clear.

[Mark Amery]

Your edit clarifies your interpretation of the two codes, which seems to match many other people's interpretation. However, I personally believe that interpretation makes little sense. The use of the phrase "If authentication credentials were provided" in the 403 description implies that a 403 can be appropriate even if no credentials were provided - i.e. the "unauthenticated" case. Meanwhile, to me the most natural interpretation of the phrase "for the target resource" being included in the 401 description is that a 401 can be used for a user who is authenticated but not authorized.

[Grant Gryczan]

What exactly is being created?

[Ruslan Stelmachenko]

RFC 7231 (Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content) changes the meaning of 403: There is no more "Authorization will not help". It says: "If authentication credentials were provided in the request, the server considers them insufficient to grant access. The client SHOULD NOT automatically repeat the request with the same credentials. The client MAY repeat the request with new or different credentials." So, Authorization (grant more permissions) will help and this answer is incorrect now (formerly was correct).

[gingerCodeNinja]

if the user is not logged in or logged in but does not have permission, and the content doesn't exist at location, sometimes you probably want to return 401/403 instead of 404, so that you don't expose what is or isn't there if the user is not authenticated and logged in. Just knowing something exists can hint toward something or break NDA. So sometimes the 404 part of this diagram should be moved under logged in/authenticated.

[Christophe Roussy]

@gingerCodeNinja yes this is the same logic as the one for 404 instead of 403, good to mention this case.

[Darren Yeats]

My reading of the latest RFC: 401 means unauthenticated; 403 can mean insufficient authorization (in which case different authentication may help) OR it can be unrelated to credentials (in which case adding or changing authentication won't help). You shouldn't infer you're authenticated on the strength of a 403 alone, but you should infer you're not authenticated if you get a 401.

[teashark]

Thank you for including the very valid no reveal cases at all levels. This is heavily context dependent of course, but I like that you've made it clear that it's possibly an option in all of those cases.

[Christophe Roussy]

@MattKocaj note that the no reveal case can sometimes be detected via subtle timing differences and should not be seen as a security feature, it may just slow down attackers or help a little with privacy.

[Chris H.]

I think you meant 302 and not "301 redirect to login".

[Kousha]

This is a great TLDR answer to this question.

[Christophe Roussy]

@ChrisH. not sure if 302 is really better than 301 for this case, maybe because it will not be cached by bots ? I suppose you are talking about SEO issues ? Those pages are not crawled anyways because the bots have no account and cannot login, the redirect is performed for users who receive links to protected pages and achieves the desired result after a login.

[Chris H.]

@ChristopheRoussy the user's browser will cache the 301 as well, which is not what we want. For example, if the user is hitting their profile page and getting redirected to login then their browser has every right to serve the login page the next time the user requests their profile page. See here for more details: stackoverflow.com/questions/9130422/…

[Christophe Roussy]

@ChrisH. I looked under the hood and the framework redirect method uses 303 See Other en.wikipedia.org/wiki/HTTP_303

[anned20]

Ironically the OWASP link now goes to a 404 page. I found something similar (I think) on owasp.org/index.php/…

[James]

Not sure it specifically "always" mean the sender was unknown. Just whatever they requested was not authorised.

[James]

Depends on the API and how access is given. But "leaking" is not a problem if it returns 401 for username/password it's the same as for a web form surely?

[Jasmine]

While your explanation looks convincing, but I am not satisfied or trsuting it coz the error 401 says authorization in name itself and you are mixing with authentication. Well, can I tell a scenario, using credentials I obtain token means authenticated successfully, and use that to access "unathorized resource" for that token. Thats unauthorized 401. What you have to say for this?

[NewNewton]

@Jasmine your concern is understandable, but the above explanation is correct. The conflict in terminology is caused by the http spec not conforming to the currently widely used definitions to the terms 'authentication' and 'authorization'. Likely caused by these definitions not being universally used the way they are now. We are stuck with the conflict and the confusion it causes. Evidence supporting this is that the default behavior of browsers is to prompt for credentials on a 401 response.

[Frank Hopkins]

@Kyle Your examples are examples of a request not being authorized. So you are actually arguing against yourself. The IP is part of your (request) identity, and you are simply not authorized by virtue of that identity parameter. An admin can easily authorize you by adding your ip to the whitelist. So your 403 use cases, use it as a means to imply that the request is not authorized, exactly in the general spirit of this answer.

[Mark Amery]

@Brian The main distinction is that you return a 401 if your system uses HTTP auth as specced in RFC 7235 (and thus you must return a WWW-Authenticate header with such a response), and a 403 otherwise.

[Mark Amery]

@MichaelBlackburn No, that's not the case. The server doesn't need to know you to return a 403. For one thing, neither the old RFC 2616 spec nor the newer RFC 7231 spec ever says that; for another, the phrase "If authentication credentials were provided in the request" in the new spec only makes sense if it's possible to return a 403 in some cases where there were not authentication credentials included in the request (i.e. cases where the server definitely does not "know you").

[Mark Amery]

This is an admirably pithy summary of the distinction described in the accepted answer. Like the accepted answer, though, it's just plain wrong. Nothing written in the HTTP spec supports this distinction and what's more for typical website login systems that don't use WWW-Authenticate and Authorization headers returning 401s isn't allowed by spec at all.

[Mark Amery]

Your "Authorization will not help" quote is from a spec that's been obsolete since June 2014. tools.ietf.org/html/rfc7231 replaced it and says the opposite - that "The client MAY repeat the request with new or different credentials." As such, it's now definitely okay to use a 403 response in "Need to authenticate" and "Authentication insufficient" scenarios.

[Mark Amery]

This is clear and straightforwardly written, but wrong. It's totally fine to return 403s when the user is not authenticated. Nothing in the spec says otherwise, and often you can't use a 401 in that situation because returning a 401 is only legal if you include a WWW-Authenticate header.

[Mark Amery]

Just not true. The current spec's description of 403 states that "The client MAY repeat the request with new or different credentials.", which contradicts your description of 403 here.

[Luca C.]

tx @MarkAmery , i slightly corrected the sentence to include maybe autentication

[James]

@MarkAmery "repeat with new or different credentials" ok so my answer still stands because a new or different request is not a "re-try" is it? If you are logged in as your own user and get a 403, then try again you will get a 403. If you logout and back in with an Admin user and now get a 200 instead, that is not a retry request. It is a different request altogether with different credentials. So my answer still stands, "you" are not allowed, "your" name is not on the list, "you" wont ever get in, "don't send a re-try request". Using different credentials is not a "re-try" it's a new request.

[Levite]

Thank you! If you want you can edit the answer. For now I put a deprecation warning at the top.

[VinyJones]

So 401 : your authentication fails And 403 : your authentication succeeds or your didn't try to authenticate (anonymous user) BUT your not allowed to access the resource

[Michael Blackburn]

@MarkAmery You are correct -- my comment (I believe, it was 5 years ago) was intended to be that the spec shouldn't be ambiguous (but I believe either it is or how it's commonly implemented is).

[PRAJIN PRAKASH]

Someone please say a solution for the same problem stackoverflow.com/questions/69449637/…

[the911s]

This is a good answer. I am a big fan of a 404 for a user trying to get a resource they don't have access to in many cases. The biggest anti-pattern would be to should show a user a forbidden code when they find a resource that exists that they aren't permissioned to and a 404 if the resource doesn't exist at all. That provides them information they likely aren't entitled to - that a resource exists with that ID. If someone is searching for a resource not in their domain: 404. Not found. Whether it exists for someone else or not.

[James]

The question states/asks "a user does not have sufficient privileges", there is no scenario I can think of where your "201" would be anything other than entirely wrong and utterly confusing for the client. Especially if my request is not related to "create", ie if I just want to login or GET something I'd expect a 200.

[Brian Cannard]

On a website where some pages are admin-access only, and user can logout and login as an ordinary user many times back and forth, when they left an admin page in a separate tab, then got back to that URL, when a front-end SPA fetches a list of admin-only accessible resources, a clean response 403 Forbidden will help to render a page that you don't have access to that and logged in as a normal user by a mistake. Stirring water is fun!