9 Most Common HTTP Errors Explained

9 Most Common HTTP
Errors Explained
Created By: Amit Kute (Quality Analyst)

Introduction
CREATED BY: AMIT KUTE (QUALITY ANALYST)Slide No. 2
Apart from the 404 error, how many other HTML error pages do you know about? Have you ever thought about what happens in the
background when you seeanyofthese HTMLerror pageson your screen?
Thosecodesaremeantto conveyimportant information to the user.It canbeuseful to know them better, especially ifyou are awebsite
owner. Usingthem properly reducesyour bounce rate, improves your searchengine ranking andgivesyou knowledgeon the performanceof
your site.
UnderstandingStatusCodes
Behind every error pageyou seeon the webthere isanHTTPstatuscodesent by the web server.Statuscodescomein the format of 3 digit
numbers.Thefirst digit marksthe classof the status code:
 1XXstatuscodeshaveinformationalpurposes
 2XXindicatessuccess
 3XXisforredirection
Noneof these three classesresult in anHTMLerror pageasin this casesthe client knowswhat to do andgoeson with the task without
hesitation. What we usuallyseeare the 4XXand5XXkind:
 4XXrepresent client-sideerrors
 5XXsindicate problems on the serverside
HTML error pages are displayed in these cases because the client has no idea about what how to move on. Let’s see what happens in the
background when something goessouth andwhat you cando about it.

Client-Side Errors (4XX)
400–BadRequest
Whenever the client sendsarequest the server isunable to understand, the 400Bad Requesterror pageshowsup. It usually happenswhen the
data sentby the browserdoesn’t respect the rulesof the HTTPprotocol, sothe webserver iscluelessabout how to processa request containinga
malformedsyntax.
When you seea400error pagethe reasonismost likely that there’s
something unstable on the client side: anot sufficientlyprotected
operating system,aninstableinternet connection,a
defective browseror acachingproblem. Soit’s alwaysagood idea to
test abityour own PCbefore youcontact the owner ofthe website.
Openthe samewebpagein adifferent browser,clearthe cache,and
checkif youare due with security updates. If you regularly meet the
400error on different sites, your PCor Macis awaiting athorough
securitycheckup.

401–AuthorizationRequired
When there’s apassword-protectedweb pagebehind the client’s request, the server responds with a401Authorization requiredcode. 401doesn’t
return aclassicalerror messageat once, but apopup that asksthe userto provide alogin-passwordcombination.
If youhavethe credentials, everything isall right, and youcangoon withoutanyproblem and get
accessto the protected site. Otherwise youare redirected to the Authorization
Requirederror page.
If youare awebsiteowner, youcanaddthe samepassword-protection to your site or apart of it
through your cPanelaccount.
Clickon the “PasswordProtect Directories”
submenuinsidethe “Security“menu boxand
choosethe web folder you want to protect. It
canbe agoodsecurity layer to restrict accessto
your admin arealike the wp-admin folder ina
WordPresssite.

403–Forbidden
Youcanencounter the 403Forbiddenerror pagewhen the server understands the
client’s request clearly, but for somereasonsrefusesto fulfil it. Thisisneither a
malformation nor an authorization problem. Byreturning the 403status codethe
server basicallyrejects the client with abig loud “No” withoutanyexplanation
Themost commonreasonisthat the websiteowner doesn’t permit visitors to browse
the file directory structure of the site. Whenthis kind of protection isenabledyou
can’t accessfolders directly onthe website.Theother frequent reasonisthat the
specificfile the client
requested doesn’t havethe permissionto be viewed from the web.
Youcanset 403protection for security reasonson your own site. It canbeuseful
to harden your site againstbeing hacked by hiding the directory structure or
files that contain vulnerable information.
Luckilymanyweb hostsprovide this serviceto their clientsby default, but if you
want to addan extra security layer,openyour cPanelaccount, navigateto the
Advanced menu box,andclick on Index Manager.
Hereyou cancustomize how your visitors view aspecificdirectory on your
site. If you chooseNoIndexing the client will receivean403error pageif it
tries to accessthe given directory.

404– Not Found
404isthe most well-known HTTPstatuscodeout there, andyou havesurely read manygreat posts about how to customize 404pages.The
browser returns a404HTMLpagewhen the server doesn’t find anything on the requestedlocation.
Thereare two main scenariosthat canresult in a404NotFound page.Eitherthe
visitor mistyped the URL,or the permalink structure of the site hasbeenchangedandthe
incoming links point to pagesthat were moved to different locations.404error pages sometimescanappearon top level URLstoo. It usually
happens when asite hasrecently moved to another webserver andthe DNSstill points to the old location. Thiskind of problem usually
Youcanfind SEOexperts on the web who claim too many404shavea
negative effect onyour site’ssearchengine ranking, but Googleclaims
that “404 errors don’t impact your site’sranking in Google,andyou
cansafely ignore them” as404sare seenasanormal part of the webby
the searchengine.
Youmaywant toreduce the number of your 404sbecausethey increase
the bounce
rate (people wholeaveimmediately) of your site. Themostcommon
solution for this isusing 301redirects for permanently removed
pages,and302sfor those that are temporarily unavailable.

408–RequestTime-Out
When the request of the client takestoo long, the servertimes out, closesthe connection,and the browserdisplaysa408RequestTime-Outerror
message.Thetime-out happensbecausethe server didn’t receive acomplete request from the client within the timeframe it wasprepared to
wait. Persistent408errors canoccur becauseof the heavyworkload on either the server or on the client’ssystem.
In somecasesboth endsof the connectionworkproperly but atemporary
internet surgeslows down the delivery of the message.Biggerwebsites tend
to customize408error pagesjust like mostof youdo, in caseof 404s.408
errors canusually be fixed by reloading the pagewith the help of the F5
button.

410–Gone
The410Goneerror pageisvery closeto the well-known 404. Both meanthat the server doesn’t find the requested file, but while 404 suggests
that the target file maybeavailable somewhere on the server, 410indicates apermanentcondition.
410showsthe client that the resource wasmadeintentionally unavailable, andthe website owner wants incoming linksto be removed from
the Web. 404isusedwhen the server is unsure if the unavailability of the file ispermanent, but 410alwaysindicates acomplete certainty.
If you are in chargeof your own server, it’s important to understand how
404sand410sare treated differently byGooglecrawlers.In this video Matt
Cutts, Google’sheadof searchspam explains the gist of this distinction. It’s a
goodidea to distinguish between 404and410to enhanceyour Google-
friendliness.

Server-Side Errors (5XX)
500–Internal ServerError
Internal ServerError isthe most well-known server error, asit’s usedwhenever the server encounters anunexpected condition that prevents it
fromfulfilling the client’s request. The500 error codeisageneric one,it’s returned when no other server-side 5XXerror codesmakeany sense.
Althoughin this casethe problem isnot on your end, youcando
somethings to resolve it such asreload the page(asthe error maybe
temporary), clearyour browser’s cache(asthe issue mayoccur with
the cachedversion of the site), anddelete your browser’s cookies
andrestart the browser.
Youcanalsocontact the webmaster (like in caseof anyother server-
side problems) –they may be grateful for your contribution but
there’s alsoachancethat they are aware of the problem and already
working onit.
If youencounter the 500error pageon your ownsite, it will be
wiseto contact yourhosting provider. Thereasonismost likely a
permissionerror, acorrupt .htaccessfile or atoo low memory
limit. If you haveaWordPresssite, the 500error canalsocaused
by athird party plugin; you cantest this by deactivating your
plugins,oneby one,until the culprit isfound.

502–BadGateway
The502error messagerepresents acommunicationproblem between two servers.It occurs when the client connectsto aserver acting asa
gateway or aproxy that needsto accessan upstream server that provides additional serviceto it. Theother server islocatedhigher in the
server hierarchy.It canbefor exampleanApacheweb server that’s
accessedby aproxyserver, or the nameserver of alarge internet
serviceprovider that’s accessedby alocal nameserver.
When youencounter the BadGatewayerror pagethe server
receivesaninvalid responsefrom anupstream server.
In most casesit doesn’t meanthat the upstream server isdown but
that the two communicating serversdon’t agreeon the protocol
about how toexchangedata. Thisusually happenswhen oneof the
machinesisincorrectly configured or programmed. Contact your
hosting provider if you see502on your ownsite.

503–ServiceTemporarily Unavailable
Youseethe ServiceTemporarilyUnavailable (sometimesOutofResources)messageanytime there’s atemporary overload on the server, or when it’s
goingthrough ascheduled maintenance. The503error codemeansthat the web server iscurrently not available. Thisis usually atemporary
condition that will be resolved aftersomedelay.
If you are awebsite owner it’s important to haveappropriate
knowledgeabout the 503status codeto properly handle scheduled
maintenance.If youdon’t handlescheduled maintenance in the
correct way,you mayhurt the searchengine ranking of your site.
Learnhow to dothis viathis tutorial onYoast’sSEOblog or this one
on moz.com.

504–GatewayTime-Out
Thereisaserver-server communicationproblem behind the Gateway Time-Outerror message, just like behindthe 502 BadGateway error code.
When the 504statuscodeisreturned there’s alsoahigher-levelserver in the background that issupposedto senddata to the server that is
connectedto our client. In this casethe lower-level server doesn’t receiveatimely response from the upstream serveritaccessed.
Thisisthe sametime-out problem that occursin caseof the 408RequestTime-Outstatuscode, but here it doesn’t happen between the client and
the server but between two serversin the backend. TheGateway Time-Outerror pageusually indicates slowcommunicationbetween the two
servers,andit canalsohappenthat the higher-levelserver iscompletely down.
As504isanetwork problem in the background only people who haveaccessto
that network cansolveit. Aswith other server-side HTTPerrors, sometimes
it’s enoughto refreshthe pagea few minutes later to tackle the issue–of
courseonly if the serviceproviderswork on the problem meanwhile.

Thank You…..!
CREATED BY: AMIT KUTE (QUALITY ANALYST) 13

9 Most Common HTTP Errors Explained

More Related Content

Similar to 9 Most Common HTTP Errors Explained

Recently uploaded

9 Most Common HTTP Errors Explained