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

Modern uploads for long-lived Web Forms apps.

AjaxUploader 5.2 gives existing ASP.NET Web Forms projects a current upload experience: the self-hosted Companion broker that keeps cloud tokens server-side, 6 built-in cloud sources, headless hooks for React, Vue, Svelte, and Angular, a content-aware image editor with AVIF/WebP output, resumable chunks, direct-to-cloud transfers, and migration-friendly 4.x compatibility.

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