If you are dealing with exceptionally large files, the standard response might time out. You can increase the timeout in your web.config or manually chunk the file output using a buffer.
Always validate that the user has permission to access the specific file before serving it. Ensure the requested path does not allow "directory traversal" (e.g., ../../web.config ). Handling Large Files and Timeout Issues download file from handler c#
If you serve various file types, use a helper method to map file extensions to MIME types (e.g., .zip to application/zip ). If you are dealing with exceptionally large files,
To get started, create a new Generic Handler (DownloadHandler.ashx) in your project. The core logic resides in the ProcessRequest method. download file from handler c#