How to properly use Bearer tokens

In the realm of web development and authentication, bearer tokens play a crucial role in securing APIs and ensuring that each request is made by an authorized entity. Often associated with OAuth 2.0, bearer tokens provide a convenient way to handle authentication and authorization without constantly prompting the user for credentials.

How to properly use Bearer tokens

Table of Contents

The Importance of Bearer Tokens

Bearer tokens offer simplicity for developers and users alike. They can be used across a variety of platforms, scaling security measures and streamlining the process for authentication checks. And, as a developer, it’s essential to understand how to use bearer tokens effectively.

Retrieving a Bearer Token

Normally, a bearer token is obtained after a successful authentication process. Here’s a simple example using cURL to retrieve a token:

    curl -X POST -H "Content-Type: application/json" \
    -d '{"username":"johndoe","password":"secret"}' \



Once you have the token, it can be used for subsequent requests to represent the authenticated user.

Using Bearer Tokens in Requests

Once you have a bearer token, you can use it to access APIs by including it in the Authorization header of your HTTP requests. Here’s how to include it in a cURL request:

    curl -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI..." \


    {"message":"Successfully accessed protected route"}

In JavaScript, you can add it to an Ajax request like so:

    const token = "eyJhbGciOiJIUzI1NiIsInR5cCI...";
    fetch('', {
      headers: new Headers({
        Authorization: 'Bearer ' + token

Best Practices for Using Bearer Tokens

To ensure optimal use of bearer tokens, follow these best practices:

  • Store tokens securely and ensure they are encrypted during transit and at rest.
  • Implement token expiration and renewal policies.
  • Use HTTPS to prevent man-in-the-middle attacks.
  • Validate tokens properly on the server side before serving any protected resources.

Security Considerations

Bearer tokens are inherently vulnerable if not handled with care since possession equals access. Enhance security by:

  • Using short-lived tokens along with refresh tokens.
  • Ensuring the token server’s authenticity is verified by the client.
  • Employing token binding technologies.

Common Mistakes

Be wary of these common pitfalls when you use bearer tokens:

  • Leaking tokens in logs or error messages.
  • Exposing tokens to the client-side or browser storage unencrypted.
  • Forgetting to validate the token with each request.


Conclusive Summary

Properly using bearer tokens is instrumental in creating secure applications. These tokens provide a powerful way to maintain state between requests in stateless HTTP applications. By following best practices and being mindful of security, developers can leverage bearer tokens to ensure secure and seamless user experiences. Remember to always handle tokens carefully to prevent unauthorized access.