How-to guides . v5.2

Scenario-based guides for common upload workflows.

Pick a recipe. Every card jumps to a working demo page with the exact server-side wiring, code-behind events, and JavaScript options needed to ship it.

Keep cloud tokens server-side with the Companion broker 5.2

Run the self-hosted multipleupload/server/companion broker so Dropbox, Box, Drive, and OneDrive OAuth happens on the server. Client secrets and access tokens never reach the browser. Zero new dependencies.

Stream remote files straight to S3 or disk 5.2

Use the broker's server-to-destination mode so remote files flow remote to broker to S3 (or the built-in fileSystemDestination) - the bytes never touch the browser.

Build a fully custom UI with headless hooks 5.2

Call useUploader() in React or Vue, use:uploader in Svelte, or UploaderService in Angular to get files, progress, status, and actions - then render every pixel yourself.

Smart-crop and export to AVIF / WebP 5.2

Content-aware focal-point crop (edge-energy heuristic, no AI), text and sticker overlays, filter presets, then export to AVIF or WebP with a quality slider and graceful fallback.

Upload directly to S3 / Azure / GCS 5.2

Browser PUTs each part to cloud storage via presigned URLs from IS3Signer / IAzureSigner / IGcsSigner. Bytes never transit IIS.

Let users import from 6 cloud sources 5.2

Enable the Drive, Dropbox, OneDrive, Box, Unsplash, and Companion-broker pickers next to local browse / drag-drop. Files stream from the cloud provider through your import endpoint.

Encrypt files in the browser (zero-knowledge) 5.2

Turn on encrypt: true. AES-GCM-256 + PBKDF2 from a passphrase. Server only ever stores ciphertext.

Survive tab close + offline 5.2

Combine persistState with the new service-worker offline queue. Network drops and tab closes resume on reconnect.

Scan uploads for malware 5.2

Wire OnFileUploaded to ClamAV / Defender / any AV CLI, or POST to the built-in /scan endpoint. Reject and quarantine infected files server-side.

Mirror upload state across tabs 5.2

Use BroadcastChannel coordination so the same dashboard reflects live progress in every open tab.

Ship Arabic / Hebrew / Persian (RTL) 5.2

Set locale to any of the 28 built-in locales. RTL languages auto-flip the layout and use mirrored progress UI.

Make uploads survive reloads

Enable IndexedDB persistence. Tab crashes and F5 resume automatically from the last completed chunk.

Crop images before upload

Rotate, flip, and crop with 8 drag handles + optional aspect-ratio lock. 100% client-side.

Save files to SQL Server

See the provider demo for a database-backed upload strategy.

Upload images with previews

Use preview, thumbnail, crop, and resize demos as starting points for image-heavy workflows.

Enable MIME checking

Combine extension filters with MIME validation for stronger client-side screening.

Build custom UI

Drive AjaxUploader from external buttons and custom progress surfaces.

Combine uploads with forms

Use the form integration demos for multi-field business workflows.

Use CoreUpload in ASP.NET Core

AjaxUploader covers Web Forms. CoreUpload is the product for ASP.NET Core applications.