v5.1 for ASP.NET Web Forms ASP.NET Core? Use CoreUpload ->

Modern uploads for long-lived Web Forms apps.

AjaxUploader gives existing ASP.NET Web Forms projects a current upload experience: resumable chunks, direct-to-cloud transfers, drag and drop, validation, progress UI, image tools, and migration-friendly 4.x compatibility.

Direct-to-cloud Resumable Validated 30 locales

Explore 119 demos Download package

Building with ASP.NET Core, Razor, Blazor, or Minimal APIs? Use CoreUpload.

7upload strategies

30built-in locales

4.xcompatibility shim

Drop zone with chunked resume

Current upload release-assets.zip

74% uploaded - 4 parallel chunks

Strategy Direct-to-S3 Signed by Web Forms. Bytes bypass IIS.

Trusted upload technology for established .NET teams

What you can ship

Production upload workflows without rebuilding the app.

Direct-to-cloud transfers

Upload directly to S3-compatible storage, Azure Blob, or Google Cloud Storage using server-generated signatures.

Resume and recover

IndexedDB-backed state lets interrupted uploads continue after reloads, tab crashes, and connection drops.

Validate before storage

Check size, extensions, MIME type, image dimensions, duplicate files, custom rules, and scan hooks.

Transport

Seven strategies, one server control.

Switch transport behavior without redesigning your upload page. Start simple, then move heavy files directly to cloud storage when the app needs it.

View features Browse demos

singleStandard multipart POST for small forms.

chunkedParallel chunks, retry, server-side assembly.

s3 / azure / gcsBrowser-direct uploads using signed URLs.

tusResumable tus 1.0 protocol support.

urlImportServer fetch with live NDJSON progress.

Uploader family

Same upload core, matched to your stack.

ASP.NET Web Forms

AjaxUploader

Server controls, Visual Studio-friendly demos, and 4.x compatibility for long-lived Web Forms applications.

ASP.NET Core

CoreUpload ->

Tag Helpers, Razor components, Minimal APIs, and .NET 8+ integration.

Standalone JavaScript

MultipleUpload ->

Zero-dependency upload UI and transport engine for any backend.

Try it in a Web Forms project today.

Download the package, open the demos, and test locally without a production license key.

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