How does a browser determine the content type received in response from an API (e.g., image, text, etc.)?

The browser determines the content type of the response from the API based on the HTTP header Content-Type, which the server sends along with the data. This header indicates the MIME type, for example:

• text/html — HTML page
• application/json — JSON data
• image/png — PNG image

Based on this, the browser chooses how to process and display the received content. For example, if it's an image, the browser will display it as a picture; if it's JSON, it may show it as text or pass it to JavaScript for processing.

Example of an HTTP header:

Content-Type: application/json; charset=utf-8

Therefore, correctly setting the Content-Type on the server is critical for the proper functioning of the client.