What are headers in rest api?

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Headers play a crucial role in REST API (Representational State Transfer Application Programming Interface) communication. They provide additional information about the request or response being sent between a client and a server. Understanding headers is essential for developers working with REST APIs as they can influence the behavior and functionality of the API. In this article, we will dive deeper into the topic of headers in REST API and explore their significance.

What are Headers in REST API?

Headers in REST API are key-value pairs that convey metadata about the request or response being sent between a client and a server. They are part of the HTTP protocol and are included in the headers section of an HTTP message. Headers provide important information such as the content type, authentication credentials, caching directives, and more.

Headers are used to provide additional context to the API requests and responses. They can be used to control caching behavior, specify the format of the data being sent or received, authenticate the client, and handle various aspects of the communication process. Headers are typically included in the HTTP request sent by the client and the HTTP response received from the server.

Commonly Used Headers in REST API

Content-Type: The Content-Type header specifies the media type of the data being sent or received. It informs the recipient about how to interpret the payload. Common values for the Content-Type header include “application/json” for JSON data, “application/xml” for XML data, and “text/plain” for plain text.

Authorization: The Authorization header is used to authenticate the client making the request. It typically contains credentials such as an API key, access token, or username and password. The server can use this header to verify the identity of the client and grant or deny access to the requested resource.

Cache-Control: The Cache-Control header is used to control caching behavior. It specifies directives for caching intermediaries (such as proxies) and the client’s own cache. The directives can include instructions on whether to cache the response, how long to cache it, and whether to revalidate it on subsequent requests.

Accept: The Accept header specifies the media types that the client can handle in the response. It allows the client to communicate its preferences to the server, indicating the formats it can understand. The server can then choose the appropriate format for the response based on the client’s preferences.

Location: The Location header is often used in HTTP responses to indicate the URL of a newly created resource. It is typically sent as part of a 201 Created response status code and provides a convenient way for the client to locate the newly created resource.


Headers in REST API are essential for conveying additional information about the request or response being sent between a client and a server. They provide important metadata that influences the behavior and functionality of the API. Understanding the commonly used headers in REST API allows developers to effectively communicate with the API and utilize its features.

In conclusion, headers play a vital role in REST API communication by providing context, controlling caching behavior, specifying data formats, authenticating clients, and more. They enhance the flexibility and functionality of REST APIs, enabling developers to build robust and efficient applications.


– developer.mozilla.org
– restfulapi.net
– www.w3.org