Difference Between Refresh Tokens and Access Tokens

Have you ever wondered how websites and apps manage to keep you logged in, even after you close them or leave for a while? The secret lies in something called refresh tokens and access tokens.

Let's imagine you're at a crowded concert venue. When you enter, you get a stamp on your hand - this stamp allows you to go between the main area and the lobby as needed without having to show your ticket each time. This stamp is like an access token - it grants you temporary access.

However, these hand stamps can smear or fade over time. That's where the refresh token comes in. The staff at the entrance has a "master stamp" they can use to renew or replace your hand stamp if it starts wearing off. This master stamp is like the refresh token - it has longer-lasting privileges to easily renew your shorter-term access.

In the digital world, access tokens and refresh tokens work in a similar way:

Access Tokens

An access token is a code or key that websites and apps issue when you log in successfully. This token gets included with each request you make, proving you have permission to access certain features or data. Access tokens don't last forever though - they typically expire within an hour or two.

This short lifespan is a security precaution. If an access token gets stolen or compromised somehow, the potential damage is limited because the token becomes useless very quickly.

Refresh Tokens

But how do websites keep you logged in for weeks or months at a time if the access token expires so frequently? That's where refresh tokens come in.

A refresh token is another coded token that has a much longer lifespan than an access token - they may be valid for 30 days, a year or sometimes with no expiration at all.

When your access token expires, your app can use the refresh token to request a fresh new access token from the server. As long as the refresh token is valid, the server will keep issuing new short-term access tokens to maintain your login session.

This separation of short-lived access tokens and long-lived refresh tokens strikes a good balance of security and convenience. The access tokens prevent prolonged access if compromised, while the refresh token allows you to re-authenticate quickly and stay logged in with minimal interruption.

So the flow works like this:

1. You log in and receive an access token and a refresh token.

2. Your access token expires after a set time.

3. Your client uses the refresh token to request a new access token from the server.

4. The server verifies the refresh token is valid and issues a new access token.

5. Your client can now use the new access token for authorized requests until it expires.

6. Repeat steps 3-5 to stay logged in until the refresh token itself expires.

So in summary - access tokens are like your temporary hand stamp to get into the event, while refresh tokens are like the master stamp used to keep issuing new hand stamps when yours starts to fade. Working together, they let web services authenticate you continuously with tight security.

Happy Reading!

Rohit Telgote