v5.2 for ASP.NET Web Forms ASP.NET Core? Use CoreUpload ->

Modern uploads for Web Forms apps that still run the business.

AjaxUploader 5.2 is the focused upload control for ASP.NET Web Forms teams that do not want to buy a whole UI suite, wire a JavaScript uploader by hand, or move sensitive files through a hosted upload service. Add resumable chunks, direct-to-cloud transfers, validation, image workflows, and migration-friendly 4.x compatibility inside the app you already have.

Companion broker 6 cloud sources Headless hooks AVIF / WebP editor

Explore 127 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.

New in 5.2

Server-side cloud tokens, headless UI, and a pro image editor.

Companion broker

A self-hosted Node/Express OAuth and file-proxy broker with zero new dependencies. Provider client secrets and access tokens stay server-side and never reach the browser. Built-in Dropbox, Box, Google Drive, and OneDrive, with proxy and server-to-destination transfer modes.

6 cloud sources

Google Drive, Dropbox, OneDrive, Box (now first-class), and Unsplash search-and-import (no OAuth popup) join the picker, all routable through the Companion broker.

Headless framework hooks

useUploader() for React and Vue, a use:uploader action for Svelte, and an UploaderService for Angular return files, progress, status, and actions so teams can build a fully custom UI.

Content-aware image editor

Focal-point smart-crop, draggable text and sticker overlays, brightness/contrast/saturation filter presets, an EXIF info panel, crop-ratio chips, and AVIF/WebP output with a quality slider and graceful fallback.

Image pipeline

EXIF auto-rotate on upload, PDF poster thumbnails in the queue, HEIC decode, presets, and URL-based transforms honored server-side in the Web Forms handler via GDI+.

UX and accessibility

Per-file rename UI, a resume-incomplete restore prompt, whole-page drop target with form auto-attach, locale auto-detect across 28 locales with RTL, and ARIA live-region announcements for WCAG.

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.

Competitive fit

Built for the gap between UI suites, JavaScript widgets, and hosted upload APIs.

AjaxUploader is for teams keeping serious Web Forms applications alive: self-hosted, server-control friendly, and priced as an uploader instead of a platform migration.

Versus UI suites

Telerik, DevExpress, Syncfusion

Suite upload controls are strongest when the team already owns the suite. AjaxUploader keeps the purchase and documentation centered on upload workflows, with Web Forms demos, handlers, events, and licensing that do not require adopting a full component platform.

Versus JS widgets

Uppy, FilePond, legacy Fine Uploader

JavaScript uploaders are flexible, but Web Forms teams still need server plumbing, validation, lifecycle events, temp storage, and deployment docs. AjaxUploader wraps that integration in a familiar ASP.NET server-control model.

Versus SaaS upload APIs

Uploadcare, Filestack, Cloudinary

Hosted media APIs are powerful for CDN and transformation pipelines. AjaxUploader fits teams that need self-hosted control, direct cloud routes, predictable licensing, and sensitive files staying inside their chosen infrastructure.

Self-hosted Handlers, temp storage, signatures, and Companion broker under your control.

Web Forms-native Server controls, postback-aware events, Web.config guidance, and Visual Studio demos.

Uploader-only pricing Perpetual licenses starting at $99 instead of a full suite or metered upload platform.

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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