[{"data":1,"prerenderedAt":925},["ShallowReactive",2],{"\u002Fblogs\u002Fa-comprehensive-guide-authentication-in-web-applications":3},{"id":4,"title":5,"body":6,"coverImage":904,"description":907,"extension":908,"meta":909,"navigation":486,"path":911,"publishedOn":912,"seo":913,"sitemap":914,"stem":923,"__hash__":924},"content\u002Fblogs\u002Fa-comprehensive-guide-authentication-in-web-applications.md","Web Authentication Methods Explained: Pros, Cons, and Best Practices (2026 Guide)",{"type":7,"value":8,"toc":897},"minimark",[9,13,16,19,32,35,49,56,60,76,79,102,105,120,143,146,167,170,179,182,189,192,195,210,213,225,228,265,288,291,321,324,393,396,404,407,413,416,428,431,435,438,441,453,464,467,493,496,499,502,542,545,559,565,585,591,606,609,615,618,621,624,628,631,640,643,654,681,684,712,719,722,731,740,747,783,790,793,807,810,818,821,827,830,838,841,844,858,861,877,881,884,887,890,893],[10,11,12],"p",{},"Authentication is one of the core building blocks of any modern system or\nproduct; without it, a product is borderline unusable. Despite its importance,\nauthentication remains a widely misunderstood concept in the field of Software\nEngineering, especially among beginners. This article aims to provide an\noverview of commonly used authentication methods for building modern\napplications.",[10,14,15],{},"To begin with, it is important to understand what \"authentication\" is and why it\nis necessary.",[10,17,18],{},"Authentication is the process of verifying and establishing the identity of a\nuser, device, or application before granting access to a system or resource. It\nensures that only authorized entities can interact with sensitive data or\nservices, and it typically involves the following steps:",[20,21,22,26,29],"ol",{},[23,24,25],"li",{},"Identification: The user claims an identity, for example, by providing an\nemail address, username, or another identifier, along with an associated\nsecret such as a password.",[23,27,28],{},"Authentication: The system verifies the identity by validating the provided\ncredentials.",[23,30,31],{},"Authorization: The system determines whether the authenticated user has the\nnecessary permissions to access protected resources.",[10,33,34],{},"In this article, we will primarily focus on the second step, i.e.,\nauthentication, and discuss commonly used methods for applications served over a\nnetwork. These methods include:",[20,36,37,40,43,46],{},[23,38,39],{},"Basic Authentication (BA)",[23,41,42],{},"Digest Authentication (DA)",[23,44,45],{},"Session-based Authentication",[23,47,48],{},"Token-based Authentication (e.g., JWTs, access\u002Frefresh tokens)",[10,50,51,55],{},[52,53,54],"strong",{},"NOTE",": You may often encounter OAuth 2.0, SSO\u002FSAML, and OIDC in discussions\nrelated to user authentication for web applications. These are not\nauthentication methods themselves but authentication\u002Fauthorization frameworks\nbuilt on top of the methods discussed above. A detailed discussion of these\ntopics is beyond the scope of this article.",[57,58,39],"h2",{"id":59},"basic-authentication-ba",[10,61,62,63,70,71,75],{},"One of the earliest and simplest mechanisms of authentication defined in the\nHTTP specification (",[64,65,69],"a",{"href":66,"rel":67},"https:\u002F\u002Fwww.rfc-editor.org\u002Frfc\u002Frfc7617",[68],"nofollow","RFC 7617",") is the\n\"Basic HTTP Authentication\" scheme. As per this specification, user credentials\n(username and password pairs) are transmitted to the server encoded as Base64\nstrings. These encoded credentials are included in the ",[72,73,74],"code",{},"Authorization"," header,\nwhich the server decodes to validate the credentials and subsequently authorize\naccess to protected resources, if applicable.",[10,77,78],{},"In other words, if a client makes the following hypothetical initial HTTP\nrequest:",[80,81,86],"pre",{"className":82,"code":83,"language":84,"meta":85,"style":85},"language-plaintext shiki shiki-themes everforest-dark","GET \u002Fapi\u002Forders HTTP\u002F1.1\nHost: example.com\n","plaintext","",[72,87,88,96],{"__ignoreMap":85},[89,90,93],"span",{"class":91,"line":92},"line",1,[89,94,95],{},"GET \u002Fapi\u002Forders HTTP\u002F1.1\n",[89,97,99],{"class":91,"line":98},2,[89,100,101],{},"Host: example.com\n",[10,103,104],{},"The server responds with the following information:",[80,106,108],{"className":82,"code":107,"language":84,"meta":85,"style":85},"HTTP\u002F1.1 401 Unauthorized\nWWW-Authenticate: Basic realm=\"orders\"\n",[72,109,110,115],{"__ignoreMap":85},[89,111,112],{"class":91,"line":92},[89,113,114],{},"HTTP\u002F1.1 401 Unauthorized\n",[89,116,117],{"class":91,"line":98},[89,118,119],{},"WWW-Authenticate: Basic realm=\"orders\"\n",[10,121,122,123,126,127,130,131,134,135,138,139,142],{},"This indicates that the server requires the client to authenticate using the\n\"Basic Authentication\" scheme for the protected ",[72,124,125],{},"orders"," resource. At this\npoint, the client may either abort the request or proceed by providing a\n",[72,128,129],{},"username"," (e.g., an email address) and a password in plaintext. These\ncredentials are concatenated in the format ",[72,132,133],{},"\u003Cusername>:\u003Cpassword>"," (e.g.,\n",[72,136,137],{},"john-doe:secret-password",") and subsequently encoded using Base64 (e.g.,\n",[72,140,141],{},"am9obi1kb2U6c2VjcmV0LXBhc3N3b3Jk",").",[10,144,145],{},"Once encoded, the client includes these credentials in the request as follows:",[80,147,149],{"className":82,"code":148,"language":84,"meta":85,"style":85},"GET \u002Fapi\u002Forders HTTP\u002F1.1.\nHost example.com\nAuthorization: Basic am9obi1kb2U6c2VjcmV0LXBhc3N3b3Jk\n",[72,150,151,156,161],{"__ignoreMap":85},[89,152,153],{"class":91,"line":92},[89,154,155],{},"GET \u002Fapi\u002Forders HTTP\u002F1.1.\n",[89,157,158],{"class":91,"line":98},[89,159,160],{},"Host example.com\n",[89,162,164],{"class":91,"line":163},3,[89,165,166],{},"Authorization: Basic am9obi1kb2U6c2VjcmV0LXBhc3N3b3Jk\n",[10,168,169],{},"The server receives the encoded credentials, decodes them, and validates them by\nperforming a database lookup. If the validation is successful, it responds to\nthe client with the following response, indicating an authenticated state for\nthe user.",[80,171,173],{"className":82,"code":172,"language":84,"meta":85,"style":85},"HTTP\u002F1.1 200 OK\n",[72,174,175],{"__ignoreMap":85},[89,176,177],{"class":91,"line":92},[89,178,172],{},[10,180,181],{},"The following diagram provides a visual representation of the specification:",[10,183,184],{},[185,186],"img",{"alt":187,"src":188},"Basic Authentication Diagram","https:\u002F\u002Fik.imagekit.io\u002Fjarmos\u002FA%20Comprehensive%20Guide%20to%20Authentication%20in%20Web%20Applications\u002Fhttp-basic-authentication.svg",[10,190,191],{},"A key caveat of this approach is that Base64-encoded credentials can be\ntrivially decoded, which introduces a significant security vulnerability. Since\nuser credentials are effectively transmitted over the network in plaintext\n(albeit encoded), intercepting and decoding them can have severe consequences\nfor systems handling sensitive information. Due to this inherent risk, such\nauthentication mechanisms are rarely used outside of controlled environments\n(e.g., intranet or air-gapped systems). Furthermore, its use without HTTPS is\nstrongly discouraged, as it exposes the system to man-in-the-middle (MITM)\nattacks, enabling attackers to intercept and compromise user credentials.",[57,193,42],{"id":194},"digest-authentication-da",[10,196,197,198,203,204,209],{},"To address the inherent security drawbacks of the \"Basic Authentication\" scheme,\n",[64,199,202],{"href":200,"rel":201},"https:\u002F\u002Fwww.rfc-editor.org\u002Frfc\u002Frfc2069",[68],"RFC 2069"," was introduced. This\nspecification was later updated to provide improved security (see\n",[64,205,208],{"href":206,"rel":207},"https:\u002F\u002Fwww.rfc-editor.org\u002Frfc\u002Frfc2617",[68],"RFC 2617","), which we will discuss in\nthis section.",[10,211,212],{},"Similar to \"Basic Authentication\", in this method the client initiates a request\nto the server with the following information:",[80,214,215],{"className":82,"code":83,"language":84,"meta":85,"style":85},[72,216,217,221],{"__ignoreMap":85},[89,218,219],{"class":91,"line":92},[89,220,95],{},[89,222,223],{"class":91,"line":98},[89,224,101],{},[10,226,227],{},"The server then responds with a challenge containing the following information:",[80,229,231],{"className":82,"code":230,"language":84,"meta":85,"style":85},"HTTP\u002F1.1 401 Unauthorized\nWWW-Authenticate: Digest\n    real=\"orders\",\n    nonce=\"f84f1cec41e6cbe5aea9c8e88d359\",\n    algorithm=SHA-256,\n    qop=\"auth\"\n",[72,232,233,237,242,247,253,259],{"__ignoreMap":85},[89,234,235],{"class":91,"line":92},[89,236,114],{},[89,238,239],{"class":91,"line":98},[89,240,241],{},"WWW-Authenticate: Digest\n",[89,243,244],{"class":91,"line":163},[89,245,246],{},"    real=\"orders\",\n",[89,248,250],{"class":91,"line":249},4,[89,251,252],{},"    nonce=\"f84f1cec41e6cbe5aea9c8e88d359\",\n",[89,254,256],{"class":91,"line":255},5,[89,257,258],{},"    algorithm=SHA-256,\n",[89,260,262],{"class":91,"line":261},6,[89,263,264],{},"    qop=\"auth\"\n",[10,266,267,268,271,272,275,276,279,280,283,284,287],{},"Unlike the server response in the case of the \"Basic Authentication\" method, the\nserver responds differently in this scenario. The ",[72,269,270],{},"WWW-Authenticate"," header\nincludes a value of ",[72,273,274],{},"Digest",", a ",[72,277,278],{},"realm"," indicating the protected resources on\nthe system, a ",[72,281,282],{},"nonce"," (a server-generated value used to prevent replay attacks),\nan algorithm, and ",[72,285,286],{},"qop"," (\"quality of protection\").",[10,289,290],{},"The client constructs the digest based on this response by computing a\n\"response\" value, which consists of two components: HA1 and HA2.",[10,292,293,294,134,297,300,301,304,305,308,309,312,313,316,317,320],{},"HA1 is derived by hashing ",[72,295,296],{},"username:realm:password",[72,298,299],{},"john-doe:orders:secret-password",") using a specified algorithm (e.g., SHA-256).\nHA2 is derived by hashing ",[72,302,303],{},"method:uri"," (e.g., ",[72,306,307],{},"GET:\u002Fapi\u002Forders","). The final\n\"response\" value is computed by hashing ",[72,310,311],{},"HA1:nonce:nc:cnonce:qop:HA2",", where\n",[72,314,315],{},"nc"," and ",[72,318,319],{},"cnonce"," represent the nonce count and a client-generated nonce,\nrespectively.",[10,322,323],{},"The computed response is then transmitted to the server as follows:",[80,325,327],{"className":82,"code":326,"language":84,"meta":85,"style":85},"GET \u002Fapi\u002Forders HTTP\u002F1.1\nHost: example.com\nAuthorization: Digest\n  username=\"admin\",\n  realm=\"orders-api\",\n  nonce=\"f84f1cec41e6cbe5aea9c8e88d359\",\n  uri=\"\u002Fapi\u002Forders\",\n  algorithm=SHA-256,\n  response=\"753927fa0d8b4e...\",\n  qop=auth,\n  nc=00000001,\n  cnonce=\"0a4f113b\"\n",[72,328,329,333,337,342,347,352,357,363,369,375,381,387],{"__ignoreMap":85},[89,330,331],{"class":91,"line":92},[89,332,95],{},[89,334,335],{"class":91,"line":98},[89,336,101],{},[89,338,339],{"class":91,"line":163},[89,340,341],{},"Authorization: Digest\n",[89,343,344],{"class":91,"line":249},[89,345,346],{},"  username=\"admin\",\n",[89,348,349],{"class":91,"line":255},[89,350,351],{},"  realm=\"orders-api\",\n",[89,353,354],{"class":91,"line":261},[89,355,356],{},"  nonce=\"f84f1cec41e6cbe5aea9c8e88d359\",\n",[89,358,360],{"class":91,"line":359},7,[89,361,362],{},"  uri=\"\u002Fapi\u002Forders\",\n",[89,364,366],{"class":91,"line":365},8,[89,367,368],{},"  algorithm=SHA-256,\n",[89,370,372],{"class":91,"line":371},9,[89,373,374],{},"  response=\"753927fa0d8b4e...\",\n",[89,376,378],{"class":91,"line":377},10,[89,379,380],{},"  qop=auth,\n",[89,382,384],{"class":91,"line":383},11,[89,385,386],{},"  nc=00000001,\n",[89,388,390],{"class":91,"line":389},12,[89,391,392],{},"  cnonce=\"0a4f113b\"\n",[10,394,395],{},"With this approach, the password is never transmitted over the network in\nplaintext; instead, only hashed values are exchanged, with the final \"response\"\nhash being sent to the server. The server may store HA1 for subsequent\nvalidations and recompute HA1, HA2, and the final \"response\" hash to compare it\nagainst the client's provided value. If the values match, the server authorizes\nthe user to access the protected resources and responds with the following:",[80,397,398],{"className":82,"code":172,"language":84,"meta":85,"style":85},[72,399,400],{"__ignoreMap":85},[89,401,402],{"class":91,"line":92},[89,403,172],{},[10,405,406],{},"The following diagram provides a visual representation of the authentication\nmechanism for better clarity:",[10,408,409],{},[185,410],{"alt":411,"src":412},"Digest Authentication Diagram","https:\u002F\u002Fik.imagekit.io\u002Fjarmos\u002FA%20Comprehensive%20Guide%20to%20Authentication%20in%20Web%20Applications\u002Fhttp-digest-authentication.svg.\u002Fimages\u002Fhttp-digest-authentication.svg",[10,414,415],{},"Some drawbacks of this method include:",[417,418,419,422,425],"ul",{},[23,420,421],{},"Susceptibility to man-in-the-middle (MITM) attacks when HTTPS is not used.",[23,423,424],{},"An attacker can authenticate to the system if the HA1 hash is compromised.",[23,426,427],{},"Nonce values require strict validation, which can be difficult to implement\ncorrectly and securely.",[10,429,430],{},"While the \"Digest Authentication\" method provides significantly better security\nthan \"Basic Authentication\", it is still not a recommended approach in modern\nsystems.",[57,432,434],{"id":433},"session-based-authentication","Session-Based Authentication",[10,436,437],{},"The previously discussed methods are not widely used today due to the\nvulnerabilities and security concerns outlined above. Instead, \"session-based\nauthentication\" is the de facto standard when building modern web applications.",[10,439,440],{},"Similar to the previous methods, in this approach the client initiates a request\nto a protected route as follows:",[80,442,443],{"className":82,"code":83,"language":84,"meta":85,"style":85},[72,444,445,449],{"__ignoreMap":85},[89,446,447],{"class":91,"line":92},[89,448,95],{},[89,450,451],{"class":91,"line":98},[89,452,101],{},[10,454,455,456,459,460,463],{},"The server responds with a ",[72,457,458],{},"401 Unauthorized"," HTTP status code. The client may\nthen either abort the request or redirect to an unprotected route (e.g.,\n",[72,461,462],{},"\u002Flogin",") responsible for handling user authentication. This route typically\npresents an HTML form to capture user credentials.",[10,465,466],{},"When the user submits the form, the credentials are transmitted to the server as\nURL-encoded form data, as shown below:",[80,468,470],{"className":82,"code":469,"language":84,"meta":85,"style":85},"POST \u002Flogin HTTP\u002F1.1\nContent-Type: application\u002Fx-www-form-urlencoded\n\nusername%3Djohndoe%0Apassword%3Dsuper-secret-password\n",[72,471,472,477,482,488],{"__ignoreMap":85},[89,473,474],{"class":91,"line":92},[89,475,476],{},"POST \u002Flogin HTTP\u002F1.1\n",[89,478,479],{"class":91,"line":98},[89,480,481],{},"Content-Type: application\u002Fx-www-form-urlencoded\n",[89,483,484],{"class":91,"line":163},[89,485,487],{"emptyLinePlaceholder":486},true,"\n",[89,489,490],{"class":91,"line":249},[89,491,492],{},"username%3Djohndoe%0Apassword%3Dsuper-secret-password\n",[10,494,495],{},"The server decodes the request body, parses the credentials, and validates them\nby performing a database lookup to verify whether the hashed version of the\nprovided password matches the stored value. If the credentials are valid, the\nserver proceeds to create a session for the user.",[10,497,498],{},"A session typically contains a unique session identifier, a user identifier\nassociated with the authenticated user, and a timestamp to enforce session\nexpiration. This session data is commonly stored in an in-memory data store such\nas Redis or a persistent database such as PostgreSQL.",[10,500,501],{},"An example schema for the session data is as follows:",[503,504,505,521],"table",{},[506,507,508],"thead",{},[509,510,511,515,518],"tr",{},[512,513,514],"th",{},"session_id",[512,516,517],{},"user_id",[512,519,520],{},"expires_at",[522,523,524],"tbody",{},[509,525,526,532,537],{},[527,528,529],"td",{},[72,530,531],{},"af6d2c82-af1a-46d7-85b7-29e28c1be109",[527,533,534],{},[72,535,536],{},"3bb1ff78-0300-4e6b-935c-a7d5797226dd",[527,538,539],{},[72,540,541],{},"1777456473",[10,543,544],{},"Once the server has generated the session data and persisted it in a database,\nit responds to the client as follows:",[80,546,548],{"className":82,"code":547,"language":84,"meta":85,"style":85},"HTTP\u002F1.1 200 OK\nSet-Cookie: session_id=c; HttpOnly; Secure; SameSite=Strict\n",[72,549,550,554],{"__ignoreMap":85},[89,551,552],{"class":91,"line":92},[89,553,172],{},[89,555,556],{"class":91,"line":98},[89,557,558],{},"Set-Cookie: session_id=c; HttpOnly; Secure; SameSite=Strict\n",[10,560,561,562,564],{},"The response sets a cookie on the client containing the ",[72,563,514],{},", along with\nvarious security attributes such as:",[417,566,567,573,579],{},[23,568,569,572],{},[72,570,571],{},"HttpOnly",", to prevent client-side JavaScript access and mitigate XSS attacks.",[23,574,575,578],{},[72,576,577],{},"Secure",", to ensure the cookie is transmitted only over HTTPS connections.",[23,580,581,584],{},[72,582,583],{},"SameSite",", to help prevent and mitigate CSRF attacks.",[10,586,587,588,590],{},"For subsequent client requests, the server can directly look up the ",[72,589,514],{},"\nin the database, validate its expiry, and authorize the user accordingly (or\nreject the request if the session has expired), thereby avoiding repeated\ncredential validation and password handling.",[80,592,594],{"className":82,"code":593,"language":84,"meta":85,"style":85},"GET \u002Fprofile HTTP\u002F1.1\nCookie: session_id=af6d2c82-af1a-46d7-85b7-29e28c1be109\n",[72,595,596,601],{"__ignoreMap":85},[89,597,598],{"class":91,"line":92},[89,599,600],{},"GET \u002Fprofile HTTP\u002F1.1\n",[89,602,603],{"class":91,"line":98},[89,604,605],{},"Cookie: session_id=af6d2c82-af1a-46d7-85b7-29e28c1be109\n",[10,607,608],{},"The following diagram provides a visual representation of the \"session-based\nauthentication\" mechanism, offering an abridged view of the process.",[10,610,611],{},[185,612],{"alt":613,"src":614},"Session-Based Authentication Diagram","https:\u002F\u002Fik.imagekit.io\u002Fjarmos\u002FA%20Comprehensive%20Guide%20to%20Authentication%20in%20Web%20Applications\u002Fhttp-session-based-authentication.svg",[10,616,617],{},"While \"session-based authentication\" addresses many of the limitations\nassociated with the \"Basic Authentication\" and \"Digest Authentication\"\nmechanisms, it is not without its own shortcomings.",[10,619,620],{},"For instance, leakage of session data can allow an attacker to authenticate to\nthe system. Session data should be kept minimal to reduce the blast radius in\nthe event of a compromise. Additionally, session identifiers should be\nregenerated upon successful authentication and invalidated upon logout; failure\nto do so can result in session fixation vulnerabilities. Improper handling of\nsession expiry can also lead to effectively unbounded session lifetimes.",[10,622,623],{},"Since sessions must be persisted in a datastore, scalability becomes a concern,\noften necessitating a shared store beyond the server's in-memory state.\nDepending on the application's scale, complexity, and user base, this can\nintroduce additional operational overhead and cost if not architected\nappropriately.",[57,625,627],{"id":626},"token-based-authentication","Token-Based Authentication",[10,629,630],{},"So far all the authenication methods we've read so far all have certain\nshortcomings which cannot be compromised with in today's day and age. Be it the\nsecurity concerns of the \"Basic Authentication\" or \"Digest Authentication\"\nmethods or the scalability concerns of \"Session-based Authentication\", they all\nhave shortcomings. To answer these shortcomings, most modern applications today\nrely on \"Token-based Authentication\" method(s).",[10,632,633,634,639],{},"In this method, the server processes the user credentials to provide the client\nwith a signed JSON Web Token (JWT). Proposed in 2015 in the\n",[64,635,638],{"href":636,"rel":637},"https:\u002F\u002Fdatatracker.ietf.org\u002Fdoc\u002Fhtml\u002Frfc7519",[68],"RFC 7519",", JWTs are signed\npieces of information transmitted between services\u002Fapplications (such as a web\napp and its API server). These tokens are digitally signed using symmetrical\n(HMAC) or assymetrical (RSA\u002FECDSA) algorithms to ensure their integrity and\nauthenticity of the information.",[10,641,642],{},"The structure of the JWT consists of three parts - The header, the payload and a\nsecret token to be used for the digital signature.",[10,644,645,646,649,650,653],{},"The header part looks very similar to the following format where ",[72,647,648],{},"alg"," defines\nthe cryptographic algorithm used for signing the token and ",[72,651,652],{},"typ"," defines the\ntype of the token used;",[80,655,659],{"className":656,"code":657,"language":658,"meta":85,"style":85},"language-json shiki shiki-themes everforest-dark","{\n  \"alg\": \"HS256\",\n  \"typ\": \"JWT\"\n}\n","json",[72,660,661,666,671,676],{"__ignoreMap":85},[89,662,663],{"class":91,"line":92},[89,664,665],{},"{\n",[89,667,668],{"class":91,"line":98},[89,669,670],{},"  \"alg\": \"HS256\",\n",[89,672,673],{"class":91,"line":163},[89,674,675],{},"  \"typ\": \"JWT\"\n",[89,677,678],{"class":91,"line":249},[89,679,680],{},"}\n",[10,682,683],{},"The payload contains claims (e.g., roles) along with relevant user-related data.\nFor example:",[80,685,687],{"className":656,"code":686,"language":658,"meta":85,"style":85},"{\n  \"sub\": \"1234567890\",\n  \"name\": \"John Doe\",\n  \"admin\": true\n}\n",[72,688,689,693,698,703,708],{"__ignoreMap":85},[89,690,691],{"class":91,"line":92},[89,692,665],{},[89,694,695],{"class":91,"line":98},[89,696,697],{},"  \"sub\": \"1234567890\",\n",[89,699,700],{"class":91,"line":163},[89,701,702],{},"  \"name\": \"John Doe\",\n",[89,704,705],{"class":91,"line":249},[89,706,707],{},"  \"admin\": true\n",[89,709,710],{"class":91,"line":255},[89,711,680],{},[10,713,714,715,718],{},"The signature component is a cryptographic value, typically represented as a\nlong alphanumeric string (e.g., 256 to 512 bits, depending on the signing\nalgorithm used). For example: ",[72,716,717],{},"super-secret-not-long-enough-string",".",[10,720,721],{},"Putting it all together, the server derives the token by signing it using a\ncryptographic algorithm such as HMAC-SHA256:",[80,723,725],{"className":82,"code":724,"language":84,"meta":85,"style":85},"hmacsha256(base64(header).encode() + \".\" + base64(payload).encode(), secret)\n",[72,726,727],{"__ignoreMap":85},[89,728,729],{"class":91,"line":92},[89,730,724],{},[10,732,733,734,739],{},"A comprehensive discussion of the JWT specification, along with its associated\nsecurity considerations, is beyond the scope of this article and warrants a\ndedicated write-up. Therefore, I will not go into further detail here and\ninstead recommend the following resource: ",[64,735,738],{"href":736,"rel":737},"http:\u002F\u002Fwww.jwt.io\u002F",[68],"jwt.io",", which\nprovides an intuitive web interface for learning about and debugging JWTs.",[10,741,742,743,746],{},"That said, similar to the login flow described in the \"session-based\nauthentication\" method, the client transmits user credentials to the server as\n",[72,744,745],{},"application\u002Fx-www-form-urlencoded"," data. If the credentials are valid, the\nserver responds with the following response body:",[80,748,750],{"className":82,"code":749,"language":84,"meta":85,"style":85},"HTTP\u002F1.1 200 OK\nContent-Type: application\u002Fjson\n\n{\n  \"msg\": \"login successful\",\n  \"access_token\": \"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTc3NzU0NjIyMH0.KytJeYrwkSQG3ayGUjnTIjajLyYCBImu1VhxxrtvmPXl5GoaLoJ6LOYfQI4M6qM9d6SVDHSe2VafUNZxnwfs2Q\"\n}\n",[72,751,752,756,761,765,769,774,779],{"__ignoreMap":85},[89,753,754],{"class":91,"line":92},[89,755,172],{},[89,757,758],{"class":91,"line":98},[89,759,760],{},"Content-Type: application\u002Fjson\n",[89,762,763],{"class":91,"line":163},[89,764,487],{"emptyLinePlaceholder":486},[89,766,767],{"class":91,"line":249},[89,768,665],{},[89,770,771],{"class":91,"line":255},[89,772,773],{},"  \"msg\": \"login successful\",\n",[89,775,776],{"class":91,"line":261},[89,777,778],{},"  \"access_token\": \"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTc3NzU0NjIyMH0.KytJeYrwkSQG3ayGUjnTIjajLyYCBImu1VhxxrtvmPXl5GoaLoJ6LOYfQI4M6qM9d6SVDHSe2VafUNZxnwfs2Q\"\n",[89,780,781],{"class":91,"line":359},[89,782,680],{},[10,784,785,786,789],{},"The client can accept the token and store it in the user's browser for\nsubsequent use. Although the token can be stored in ",[72,787,788],{},"localStorage",", this is\ngenerally not recommended-especially if it contains sensitive information.\nInstead, it is preferable to store the token in a secure cookie.",[10,791,792],{},"For subsequent requests to protected routes, the client can retrieve the token\nfrom browser storage and include it in the request as follows:",[80,794,796],{"className":82,"code":795,"language":84,"meta":85,"style":85},"GET \u002Fprofile HTTP\u002F1.1\nAuthorization: Bearer \"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTc3NzU0NjIyMH0.KytJeYrwkSQG3ayGUjnTIjajLyYCBImu1VhxxrtvmPXl5GoaLoJ6LOYfQI4M6qM9d6SVDHSe2VafUNZxnwfs2Q\"\n",[72,797,798,802],{"__ignoreMap":85},[89,799,800],{"class":91,"line":92},[89,801,600],{},[89,803,804],{"class":91,"line":98},[89,805,806],{},"Authorization: Bearer \"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImlhdCI6MTc3NzU0NjIyMH0.KytJeYrwkSQG3ayGUjnTIjajLyYCBImu1VhxxrtvmPXl5GoaLoJ6LOYfQI4M6qM9d6SVDHSe2VafUNZxnwfs2Q\"\n",[10,808,809],{},"The token sent to the server contains user-related information (excluding\nsensitive data such as passwords), along with its expiry, claims\u002Froles, and the\ncryptographic signature used to sign it. This encoded information is validated\nby the server, and if the validation is successful, the server responds to the\nclient with the following:",[80,811,812],{"className":82,"code":172,"language":84,"meta":85,"style":85},[72,813,814],{"__ignoreMap":85},[89,815,816],{"class":91,"line":92},[89,817,172],{},[10,819,820],{},"The following diagram provides an abridged representation of the process,\nillustrating its underlying flow and logic:",[10,822,823],{},[185,824],{"alt":825,"src":826},"Token-Based Authentication Diagram","https:\u002F\u002Fik.imagekit.io\u002Fjarmos\u002FA%20Comprehensive%20Guide%20to%20Authentication%20in%20Web%20Applications\u002Fhttp-token-based-authentication.svg",[10,828,829],{},"As discussed, \"token-based authentication\" addresses many of the limitations\nobserved in earlier methods:",[20,831,832,835],{},[23,833,834],{},"No sensitive data (such as passwords) is transmitted over the network, and\nsecure cryptographic algorithms are used to ensure integrity and\nauthenticity.",[23,836,837],{},"No session state is stored in a server-side database, allowing the system to\nremain stateless and scale without significant bottlenecks.",[10,839,840],{},"These advantages have contributed to JWTs gradually replacing even\n\"session-based authentication\" in many modern architectures since their\nintroduction.",[10,842,843],{},"However, \"token-based authentication\" is not a silver bullet. Like the\npreviously discussed methods, it has its own set of caveats:",[417,845,846,849,855],{},[23,847,848],{},"JWTs encode claims and metadata using Base64, which is easily decodable.\nTherefore, sensitive information such as passwords must never be included in\nthe token payload.",[23,850,851,852,854],{},"Tokens are effectively handed over to the client and cannot be directly\ncontrolled once issued. Storing them in insecure locations such as the\nbrowser's ",[72,853,788],{}," is discouraged; secure cookies are the recommended\napproach.",[23,856,857],{},"Tokens are inherently difficult to invalidate, which can lead to prolonged\nauthenticated sessions. This can be mitigated by maintaining a token\nrevocation list, enforcing expiry timestamps, and validating them on the\nserver. A more robust approach involves issuing short-lived access tokens\nalongside refresh tokens.",[10,859,860],{},"In practice, for most modern applications, \"token-based authentication\" is often\nthe preferred approach unless constrained by specific requirements, in which\ncase \"session-based authentication\" remains a viable alternative.",[10,862,863,864,869,870,316,873,876],{},"For example, many public-facing APIs (such as the\n",[64,865,868],{"href":866,"rel":867},"https:\u002F\u002Fdevelopers.reddit.com\u002Fdocs\u002Fcapabilities\u002Fserver\u002Freddit-api",[68],"Reddit API",")\nrequire environment variables like ",[72,871,872],{},"CLIENT_SECRET",[72,874,875],{},"ACCESS_TOKEN"," for\nautomated authentication. Under the hood, these services use such credentials in\nplace of traditional username\u002Fpassword pairs to issue and manage tokens\nassociated with the client or application.",[57,878,880],{"id":879},"final-words","Final Words",[10,882,883],{},"Understanding the various authentication mechanisms used in modern web\napplications along with their trade-offs and appropriate usage patterns can be\nnon-trivial, particularly during the early stages of a software engineering\ncareer. This article consolidates those concepts into a single, structured\noverview, with the intent of serving as a practical reference for both beginners\nand practitioners.",[10,885,886],{},"It is also worth clarifying that terms such as OAuth 2.0, OpenID Connect (OIDC),\nand SSO are often misinterpreted as authentication methods. In reality, these\nare higher-level authentication and authorization frameworks built on top of\nunderlying mechanisms such as token-based authentication. A detailed discussion\nof these frameworks is beyond the scope of this article and is best addressed\nseparately.",[10,888,889],{},"In conclusion, selecting an authentication strategy is a matter of aligning\nsecurity requirements, scalability constraints, and system architecture. There\nis no universally optimal solution since each approach involves trade-offs that\nmust be evaluated in context.",[10,891,892],{},"If you have any questions or encountered challenges while understanding these\nconcepts, feel free to reach out. Feedback and discussion are always welcome.",[894,895,896],"style",{},"html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}",{"title":85,"searchDepth":98,"depth":98,"links":898},[899,900,901,902,903],{"id":59,"depth":98,"text":39},{"id":194,"depth":98,"text":42},{"id":433,"depth":98,"text":434},{"id":626,"depth":98,"text":627},{"id":879,"depth":98,"text":880},{"url":905,"alt":906},"https:\u002F\u002Fik.imagekit.io\u002Fjarmos\u002FA%20Comprehensive%20Guide%20to%20Authentication%20in%20Web%20Applications\u002Fa-comprehrensive-guide-to-authentication-in-web-apps.svg","A comprehensive guide to authentication in web applications.","Comprehensive guide to authentication in web applications, from Basic and Digest Auth to sessions and JWTs. Learn how these mechanisms work, their security trade-offs, and how to apply them effectively in modern, scalable system architectures.","md",{"status":910},"published","\u002Fblogs\u002Fa-comprehensive-guide-authentication-in-web-applications","2026-04-25",{"title":5,"description":907},{"loc":915,"images":916,"lastmod":921,"changefreq":922,"priority":92},"\u002Fa-comprehensive-guide-authentication-in-web-applications",[917,918,919,920],{"loc":188},{"loc":412},{"loc":614},{"loc":826},"2026-05-01","yearly","blogs\u002Fa-comprehensive-guide-authentication-in-web-applications","ogq7CLSuNhx0VlCW73AaD92FNv0-8mIpyczOK_L7Gws",1788263772962]