I am a complete newbie in API testing. Now, while sending a GET or POST request , we need to authorize the calling project. How does it work internally and what's the difference between API key and a Token?

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  • Voting for closing because this question is about software engineering, not testing. @test234, I suggest asking this question on Stack Overflow. Apr 16 at 17:46

2 Answers 2


API testing requires careful consideration of authorization, which is an important aspect of the process. When it comes to authorizing a client to access an API, there are two common ways of doing so: Bearer Token and API Key.

A Bearer Token is a type of access token that is generated by the server and provided to the client. It allows the client to access the API by presenting it with the request headers. Typically used in OAuth 2.0 authentication flow, Bearer Tokens are preceded by the word 'Bearer' in the authorization header, such as Authorization: Bearer <token>.

On the other hand, an API Key is a unique identifier that is provided to the client by the server. It is a simple string of characters used to authenticate the client to the server. API Keys can be restricted to specific endpoints or actions and are usually generated by the developer or the API provider. The API Key is passed as a query parameter or in the request header, such as X-API-KEY: <key>.

The main difference between Bearer Token and API Key authorization lies in their use. Bearer Tokens are used for authentication purposes, while API Keys are used for authorization purposes. Bearer Tokens authenticate the client and provide access to the API resources, while API Keys grant access to specific endpoints or actions.

In Postman, both Bearer Token and API Key can be used for authorization. To use Bearer Token, you need to add Authorization header with the value Bearer <token> in request headers. To use API Key, you need to add the API key as a query parameter or in the request header.

Here are some useful resources to learn more about Bearer Token and API Key authorization in API testing:

I hope this helps clarify the differences between Bearer Token and API Key authorization in API testing!


API key authorization is a simple way to authenticate an API request, where a secret key is passed in the request header to authenticate the client. This means that the server checks the key and allows access to the API resources if the key is valid. On the other hand, Bearer token authentication is a more secure and flexible way to authenticate a client. Here, the server provides the client with a token after successful authentication. This token is passed in the request header to access the API resources. The bearer token can also be used to authenticate multiple API requests and is valid for a certain duration. Additionally, bearer tokens can be revoked by the server to stop the client's access to the API resources.

I remember when I was working on an API project, we initially used API key authorization. But later, we switched to bearer token authentication for enhanced security and flexibility. Bearer tokens allowed us to authenticate multiple API requests without repeatedly sending the API key in each request header, which reduced the load on the server. Also, the bearer tokens had a validity period, which ensured that only authorized clients were able to access the API resources during that period. So, if you're planning to develop a scalable and secure API, I would suggest going for bearer token authentication in Postman.

I hope this explanation helps you understand the difference between bearer token and API key authorization in Postman API testing. Feel free to ask me if you have any more questions. Good luck with your API testing!

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