JWT vs. OAuth: Their Differences & Relationship

Auth ThoughtsJanuary 24, 2026

Alex Brown

Content Marketing Manager

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When building secure web and mobile applications, authentication and authorization are two pillars you can’t ignore. Developers often encounter two common terms in this space: JSON Web Tokens (JWT) and Open Authorization (OAuth). While they’re sometimes mentioned in the same breath, they serve different purposes. JWT is a token format, while OAuth is a framework for granting access without sharing passwords. They can be used separately or combined, depending on your goals. But all developers need to know the relationship between them.

This guide unpacks JWT’s key differences, common use cases, and how they can work together so you can choose the right approach for your application’s security and user experience.

Below, we’ll cover:

A JWT vs OAuth overview
Definitions for JWT and OAUth
A deep comparison of JWT vs OAuth
When to use JWT, OAuth, or both

JWT vs. OAuth at a glance

The biggest differences between JWT and OAuth stem from their nature. While JWT is a format for tokens, OAuth is a platform on which JWT and other tokens function. However, since they are often used together and/or interchangeably, there is considerable overlap between them.

Here is how each tool stacks up across some of the most important categories for developers:

	JWT	OAuth
What it is	A compact, URL-safe token format for securely transmitting claims between parties	A delegated authorization framework for granting controlled access without sharing credentials
Primary purpose	Transport and verification of claims (identity, permissions, etc.)	Securely grant and manage access to resources or APIs
Scope	Defines the structure and signing of the token	Defines the process for obtaining and using tokens
Use cases	Stateless authentication, API access, ID tokens in OpenID Connect	Third-party API access, social login, multi-service access control
Token format	Always a JWT	Can be JWT or opaque token
State management	Typically stateless and self-contained	Can be stateless (JWT) or stateful (opaque token)
Revocation	Harder to revoke before expiration without a denylist	Easier with token introspection and refresh tokens
Common pairing	Often used for ID and access tokens in OAuth/OIDC flows	Often issues tokens in JWT format

What is JWT?

JWTs use JavaScript Object Notation (JSON) to transmit claims securely between parties in a compact, URL-safe format. As an open standard, JWT is widely used for authentication and authorization because it can carry identity information and permissions in a self-contained way, removing the need for repeated database lookups.

A JWT consists of three parts:

Header – Identifies the token type and the signing algorithm (e.g., HS256, RS256).

Payload – Contains claims such as iss (issuer), sub (subject), exp (expiration), along with optional custom claims like user roles or permissions.

Signature – Created by combining the header and payload with a secret or private key to verify the token’s integrity and authenticity.

In terms of utility, JWTs are often used for ID tokens in OpenID Connect (OIDC) and access tokens in OAuth-protected APIs.

JWTs are lightweight and work well in stateless systems, which are key advantages. However, there are also some potential disadvantages to using JWTs in any system. They can be harder to revoke before expiration, may become large if overloaded with claims, and are vulnerable if keys are weak, algorithms are misconfigured, or claims aren’t validated.

Diagram titled JWT Lifecycle on a dark blue gradient background showing the interaction between an Application, an Authorization Server, and a Resource Server labeled REST API, where step 1 shows the Application requesting a JWT from the Authorization Server, step 2 shows the Authorization Server authenticating the user and generating the JWT, step 3 shows the Authorization Server sending the JWT back to the Application, step 4 shows the Application storing the JWT, step 5 shows the Application sending the JWT in every request to the Resource Server, step 6 shows the Resource Server verifying the JWT, and step 7 shows the Resource Server sending a response back to the Application if the JWT is valid, with arrows indicating the direction of each step and Descope branding visible in the bottom right corner. — Fig: JWT lifecycle

In a typical JWT auth flow, a user logs in, the server verifies their credentials, issues a signed JWT, and the client stores it (often in an HTTP-only cookie). On future requests, the client sends the JWT so the server can verify its signature and claims before granting access.

What is OAuth?

OAuth is a delegated authorization framework that allows applications to obtain limited access to a user’s resources without sharing their credentials. Instead of handing over a password, users grant an application permission to act on their behalf by issuing access tokens. These tokens can be in various formats, including JWT.

OAuth relies on four key roles:

Resource owner: The user who grants permission for an application to access their data.
Client: The application requesting access to the protected resources.
Resource server: The server hosting the data or API being accessed.
Authorization server: The server that authenticates the user and issues access tokens.

Common OAuth flows include:

Authorization Code with PKCE: Recommended for browser-based and mobile apps, replacing the implicit flow for better security.
Client Credentials: Used for server-to-server communication without user interaction.
Device Code: Designed for browserless or input-constrained devices like smart TVs, allowing the user to authorize access on a separate device.
Implicit: Now deprecated in favor of more secure alternatives like Authorization Code with PKCE.

A familiar example is when a project management app connects to a user’s cloud storage service, such as Google Drive or Dropbox, to access files on their behalf without the user sharing their password. OAuth handles the secure permission grant and token exchange that makes this possible.

Fig: Sequence diagram of authorization code flow

OAuth’s benefits include flexibility, fine-grained access control through scopes, and the ability to revoke or refresh tokens as needed. However, improper implementation can lead to OAuth issues like token theft or redirect manipulation, which can be mitigated with best practices such as strict redirect URI validation, short-lived access tokens, secure storage, and multi-factor authentication (MFA).

OAuth vs. JWT comparison

While JWT and OAuth are often mentioned together, they serve different purposes. JWT is a token format, while OAuth is a framework for delegated authorization. In practice, OAuth can use JWTs as access or ID tokens, but JWTs can also be used outside of OAuth.

Key differences

Purpose – JWT defines how to structure and sign tokens that carry claims. OAuth defines how applications can obtain and use access tokens to act on behalf of a user or service.

Use case – JWTs are used to securely transmit claims, often for authentication or authorization. OAuth is used to grant controlled access to resources without sharing passwords.

Relationship – OAuth can issue tokens in JWT format, but JWT itself is not an alternative to OAuth.

State management – JWTs are typically self-contained and stateless. OAuth can be implemented with either self-contained tokens (JWT) or stateful, opaque tokens.

Revocation – JWTs are harder to revoke mid-lifecycle unless short expirations or deny lists are used. OAuth with opaque tokens can support real-time revocation via token introspection.

In short, JWT is the envelope that can carry information, and OAuth is the process for securely granting and managing access. Many modern systems use them together—for example, OAuth 2.0 with OIDC often issues ID and access tokens as JWTs.

When to use JWT, OAuth, or both

Choosing between JWT, OAuth, or both depends on your application’s needs. OAuth is a bigger, more comprehensive system that offers greater security. JWTs offer greater ease of access and are usable in more contexts—however, they require caution.

It’s important to remember that JWT and OAuth are not mutually exclusive. In fact, they are often used together. OAuth 2.0 defines how an application obtains access tokens, which are often formatted as JWTs. For example, in an OAuth flow with OIDC, the authorization server might issue an ID token (always a JWT in OIDC) and an access token (often a JWT) to the client.

Conversely, it’s also worth noting that JWTs can be used without OAuth, and OAuth does not require JWTs—opaque tokens are a common alternative. Below are the best use cases for each.

When to use JWT

Dev teams typically turn to JWT when their need for speed and accessibility outweighs security concerns. For example, if your app needs a lightweight, self-contained token format that can be validated without a database lookup, then JWT auth is probably best. Other use cases include:

Your application benefits from stateless authentication.

You can accept limited mid-lifecycle revocation and rotate short-lived tokens.

In these instances, using just JWT and not OAuth might be most beneficial.

When to use OAuth

Developers most often opt for OAuth, with or without JWT, when there is a pressing functionality or security need. OAuth simply does more, even if it is more burdensome to use.

Some scenarios where OAuth makes more sense than JWT include:

You need delegated access to APIs without sharing passwords.

Your application requires fine-grained access control using scopes.

You want the ability to revoke and refresh tokens easily.

You’re enabling social login or multi-service access (typically via OAuth + OIDC)

In these cases, it probably makes more sense to use OAuth and not JWT.

When to use JWT and OAuth together

As noted above, JWT and OAuth are far from mutually exclusive. They’re often used together, and they arguably work better this way, combining the best of both worlds and covering gaps.

Here are some of the biggest reasons to use JWT and OAuth together:

You want OAuth’s security combined with JWT’s portability and self-contained claims.

You’re implementing OIDC, which uses OAuth 2.0 flows and issues JWT ID tokens.

You need scalable login and authorization flows across multiple applications or services.

Using JWT and OAuth together combines their strengths: OAuth’s delegated access model and JWT’s compact structure. However, this requires considering the security requirements of each. JWTs need short expiration times, strong signing keys, and validated claims; OAuth deployments should enforce strict redirect URI checks, scope-based access control, and secure token storage.

Implement JWT and/or OAuth easily with Descope

JWT and OAuth each play an important role in modern app security. JWT provides a compact, verifiable way to transmit claims, while OAuth offers a framework for granting and managing access without exposing credentials. They’re powerful on their own, but even more effective when used together. Deciding between them depends on a project’s or team’s specific needs.

Implementing JWT and/or OAuth correctly requires more than just choosing the right standard; it means configuring each step for security, scalability, and ease of use. Descope, a customer identity and access management (CIAM) platform, makes this easier by providing no-code and low-code tools to build auth flows that leverage JWT, OAuth, and other protocols securely.

With Descope, you can deliver frictionless login experiences across all your apps in just a few lines of code. Sign up for a Free Forever account or book a demo with our experts.