What are the pros and cons of using JWTs for authentication?

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Anubhav Kumar · Answer

Using JWTs (JSON Web Tokens) for authentication has clear 
pros and cons depending on your application's needs. Here's a breakdown:
Pros of Using JWTs
1. Stateless Authentication
No server-side session storage required.The token contains all the user info (claims) needed.
2. Scalable
Great for distributed systems and microservices.No need to share session state between servers.
3. Compact and URL-safe
Encoded as Base64Url strings.Can be stored in cookies, headers, or even URLs.
4. Cross-language support
JWT is an open standard (RFC 7519) supported in most languages (C#, Node.js, Python, etc.).
5. Custom Claims
You can embed user roles, permissions, etc., directly in the token.
6. Signed and Optionally Encrypted
Tokens are signed to prevent tampering.Can be encrypted (JWE) for added confidentiality.
Cons of Using JWTs
1. Token Revocation is Hard
JWTs are stateless, so once issued, they can’t be easily revoked (e.g., during logout).You need additional strategies (e.g., token blacklists or short expirations + refresh tokens).
2. Larger Size
JWTs are larger than session IDs, since they include header, payload, and signature.
3. Token Storage Risks
If stored in localStorage, tokens are vulnerable to 
XSS attacks.If stored in cookies, they're vulnerable to CSRF if not handled carefully.
4. No Built-in Expiry Renewal
JWTs don’t update expiration automatically like server sessions.Requires a refresh token system to re-authenticate.
5. Overexposure Risk
If a token is compromised, it can be used until it expires.That's why short-lived tokens + refresh tokens are best practice.
JWT is Best When:
You have a stateless API (e.g., REST or GraphQL).You need cross-domain authentication (e.g., SSO).You're working with mobile apps or SPAs (single-page applications).
JWT is Not Ideal When:
You need real-time session invalidation (like forced logout).You’re building a simple monolithic web app with built-in session handling.

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What are the pros and cons of using JWTs for authentication?

Anubhav Kumar

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2 Answers

Pros of Using JWTs

1. Stateless Authentication

2. Scalable

3. Compact & URL-safe

4. Cross-language support

5. Custom Claims

6. Signed & Optionally Encrypted

Cons of Using JWTs

1. Token Revocation is Hard

2. Larger Size

3. Token Storage Risks

4. No Built-in Expiry Renewal

5. Overexposure Risk

JWT is Best When:

JWT is Not Ideal When:

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