ASP.NET Core upload platform

Multiple file uploads without the clunky legacy UI.

CoreUpload replaces the stock file-input with a modern, drag-and-drop experience. 30+ built-in features: chunked uploads, pause/resume, client-side image resize/crop/watermark, EXIF auto-orient, MIME validation via magic bytes, dark mode, i18n, toast notifications — all wired into ASP.NET Core middleware with zero external dependencies.

Explore Demos Download Package

15k+ Customers

60+ Countries

Low RAM Streaming I/O

Upload Preview

Core capabilities

Everything you need to handle file uploads in production ASP.NET Core applications — 30+ features built in.

Batch file selection

Let users select dozens of files in a single dialog. The uploader queues them, shows individual progress, and handles retries with exponential backoff.

Drag and drop

Drag files or entire folders from the desktop. Full-page drop overlay, visual drop zone highlighting, and recursive folder traversal.

Client-side image processing

Resize, crop, rotate, compress, and watermark images in the browser before upload. Read EXIF data and auto-orient photos from mobile devices.

Chunked uploads with pause/resume

Break large files into chunks, pause and resume at will, and persist state to localStorage. Files stream to disk with no RAM buffering.

Validation and security

MIME detection via magic bytes, extension filtering, size limits, image dimension checks, duplicate detection with CRC32/SHA-256 hashing.

Dark mode, i18n, and theming

30+ CSS variables, full dark mode, toast notifications, lightbox preview, confirmation dialogs, and runtime locale switching. Zero dependencies.

Built for production

Ship upload features with confidence on ASP.NET Core 8 and later.

⚙

ASP.NET Core integration

Tag Helpers, middleware pipeline, dependency injection, and IFormFile-compatible streaming. Fits right into your existing architecture.

☁

Kestrel & IIS deployment

Deploy behind IIS reverse-proxy or run directly on Kestrel. Linux and Windows containers fully supported with no platform-specific workarounds.

📷

Image processing pipeline

Resize, crop, rotate, compress, watermark, and auto-orient via EXIF — all in the browser before upload. Video thumbnail extraction included.

Quick start

Add the Tag Helper to any Razor page and you are ready to accept uploads.

<core-upload asp-upload-url="/api/upload/upload"
               asp-extensions=".jpg,.png,.gif,.pdf,.docx"
               asp-max-size="5MB"
               asp-multiple="true">
</core-upload>

Install via NuGet: dotnet add package CoreUpload