Access and Refresh Tokens: A Practical Guide

You implemented authentication with a single long-lived token for your application.

But you are getting feedback from users and noticing it yourself — that you need to log in again on the platform after a period of time. It is introducing friction in your application regularly.

Now, either you accept this trade-off or start learning about a solution to improve the user experience: access and refresh tokens.

Problems With a Single Long-Lived Token

Apart from the UX trade-off, what other problems exist with this implementation? Let's discuss the two main concerns.

1. Security

• If the user token is stolen, you cannot do anything to protect the user account, as there is no state maintained related to authentication on the server side.
• The attacker will have access to the user account until the token expires, which increases the scope of damage.
• You cannot invalidate all sessions for a user if the account is compromised.

2. Stale Claims in the Token

• You stored a role in the token, and in between that time period, if you ban them or their subscription ends, you cannot update or revoke their access until the token is no longer valid.
• Or you need to set up another service to call the database or check from cache whether the claim is still valid — which kills the benefit of the stateless nature provided by JSON Web Tokens.

How Access and Refresh Tokens Work

With access and refresh tokens, the access token is a short-lived token used to authenticate your identity on the server. The refresh token is a long-lived token that is only used to issue new access tokens and cannot be used to authenticate your identity on the server.

Both depend on the business use case and how you use them. Above is a general guideline you can follow.

Case 1 and 2: Valid Access Token and Token Refresh

Case 1 — client sends a request with a valid access token and receives a response. Case 2 — access token is invalid, client uses refresh token to get a new access token and retries the request

Case 3: Both Tokens Invalid

Case 3 — both access and refresh tokens are invalid, server returns 401, and the client logs out the user and redirects to login

Implementation Decisions

While implementing an access and refresh token strategy, you will be making multiple decisions, such as:

1. Will you rotate the refresh token while issuing a new access token?
2. How will you manage the data in the database — what tables will you use?
3. Where will you store access and refresh tokens on the client and server?
4. How will tokens be sent from client to server?
5. What happens when a used token is sent again to the server?

And many more questions to answer.

Trade-offs

Yes, this approach gives you more control and is more secure than one long-lived token — but it is complex to implement, whereas a single long-lived token is easy.

You need to make the decision based on your use case and understanding of the trade-offs.

Why This Matters

This way, when you implement third-party services like Clerk, Auth0, and Firebase, you will know what is happening under the hood and will not treat them like a black box.

Consider this blog as a starting point, not the endpoint, for learning about access and refresh tokens.

I will soon be writing another blog with the implementation details. Stay tuned — follow me on X and LinkedIn, or read my other blogs.