FileReader API
The FileReader API is a web API that allows web applications to asynchronously read the contents of files stored on the user's computer. It provides methods to read files as text, data URLs, binary strings, or ArrayBuffers, enabling client-side file processing without server uploads. This API is commonly used for tasks like image previews, text file parsing, or client-side data validation.
Developers should use the FileReader API when building web applications that require client-side file handling, such as image upload previews, CSV/JSON file parsing before submission, or document viewers. It's essential for improving user experience by providing immediate feedback on file content and reducing server load by processing data locally. Use it in forms, drag-and-drop interfaces, or any feature where users need to interact with local files.