Server Control Basics

Demo uploads land in a temporary store and are swept after 60 minutes. To keep files, handle FileUploaded — see Single File for the complete save pattern.
Server Control Basics

The <au:AjaxFileUpload> server control provides a declarative way to add file uploads. Use properties to configure behavior without writing JavaScript.

What you should see: the server control's most common properties in one place - 5 MB cap, 5-file limit, allowlist - with a reference table underneath.
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<au:AjaxFileUpload ID="Uploader1" runat="server"
 AllowMultiple="true"
 MaxFileSize="5MB"
 AllowedExtensions=".jpg,.png,.gif,.pdf"
 MaxFileCount="5"
 ButtonText="Choose Files"
 AutoUpload="true"
 ShowProgress="true" />
Common Properties
Common AjaxFileUpload server control properties
PropertyDescription
AllowMultipleAllow selecting multiple files
MaxFileSizeMaximum file size (e.g. "5MB")
AllowedExtensionsComma-separated allowed extensions
MaxFileCountMaximum number of files
AutoUploadStart uploading immediately on selection
ShowProgressShow upload progress bar
EnableDropZoneEnable drag-and-drop file selection
ShowThumbnailsShow image thumbnails in queue
ButtonTextCustom text for the upload button