S3 Lite

A lightweight, fast S3 browser for Windows built with C# + WinForms + .NET 10. Single executable, ~4.5 MB.

Requirements

• Windows 10 / 11
• .NET 10 Desktop Runtime

Getting Started

1. Download S3Lite.exe from Releases
2. Run S3Lite.exe
3. Click Connect, enter your credentials and click Save Profile

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Features

Connection & Authentication

• Access Key / Secret Key authentication
• Environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY)
• AWS profile support (~/.aws/credentials)
• Save and manage multiple named connection profiles
• Auto-connect to last used profile on startup
• S3-compatible endpoints (MinIO, Backblaze B2, Cloudflare R2, Wasabi, etc.)
• Force path-style addressing, Dual-Stack (IPv4/IPv6), Transfer Acceleration options

Bucket Management

• List, create, and delete buckets
• Add external buckets (buckets you don't own) with auto region detection
• Bucket Properties dialog — owner, creation date, region, object/folder counts, total size, versioning, logging, replication, encryption, Object Lock, requester pays, storage class breakdown, uncompleted multipart uploads
• Change storage class for all objects in a bucket (STANDARD, STANDARD_IA, ONEZONE_IA, GLACIER, GLACIER_IR, DEEP_ARCHIVE, INTELLIGENT_TIERING)
• Create bucket options — Block Public Access, Disable ACLs, Object Lock (Governance / Compliance mode, days or years retention)

File & Folder Operations

• Browse buckets and folders with back/forward navigation history
• Upload — toolbar button, or drag and drop files/folders from Windows Explorer
• Download — single file, multi-select, folders (recursive, preserves directory structure), or entire bucket
• Delete files and folders (recursive)
• Rename files and folders (server-side copy + delete)
• New folder creation
• Copy / Move all files to another bucket (server-side, no bandwidth used)
• Restore from Glacier — for GLACIER, DEEP_ARCHIVE, GLACIER_IR objects

Transfer Queue

• Parallel upload and download queue with configurable concurrency limits
• Multipart uploads — automatic for files above configurable threshold (default 16 MB)
• Up to 128 parallel parts per multipart upload
• Pause / Resume transfers (resumes from where it left off using saved upload ID)
• Cancel with automatic multipart cleanup on S3
• Progress bar showing percentage, part count, file size, and transfer speed

GZip Compression Rules

• Rule-based automatic GZip compression before upload
• Wildcard bucket mask (e.g. *, my-bucket)
• Wildcard file mask (e.g. *.html, *.css, assets/*)
• Compression level 1–9 (1 = fastest, 9 = best compression, default 6)
• Sets Content-Encoding: gzip automatically — browsers decompress transparently
• Stores original file size as metadata — compression ratio shown in File Properties

File Preview

• Double-click or right-click → Preview (non-modal window)
• Images — PNG, JPG, JPEG, GIF, BMP, WEBP, TIFF, ICO (zoom fit)
• Text / Code — TXT, LOG, MD, JSON, XML, YAML, CSV, HTML, CSS, JS, TS, PY, CS, Java, C/C++, SQL, ENV and more
• Configurable max preview size (default 10 MB)
• Handles Content-Encoding: gzip transparently

File Properties

• Right-click → Properties — Name, S3 URI, ETag, Size, Storage class, Last modified, Content type
• Server-side encryption status (SSE-S3, SSE-KMS, DSSE-KMS)
• Client-side compression status with compression ratio and original file size
• Owner (from ACL), Version ID, Cache-Control, custom x-amz-meta-* metadata
• Right-click any row to copy value or property + value to clipboard

Web URL Generator

• Right-click file(s) → Generate Web URL
• HTTPS toggle
• Expiration: no expiry / expires in N minutes / expires on exact date
• Hostname: default AWS dualstack / custom / bucket-as-host
• Live URL preview, copy to clipboard, multi-file batch

Permissions (ACL)

• Right-click file → Edit Permissions — Owner / Authenticated Users / Everyone × Read / Write / Read ACL / Write ACL / Full Control
• Make Public and Make Private presets

File List

• Columns: Name, Size, Last Modified, Type (Windows shell description), Storage Class
• Click any column header to sort (ascending / descending with ▲/▼ indicator)
• Folders sorted before files, type and storage class hidden for folders
• Shell icons per file extension (same as Windows Explorer)
• Real-time search/filter bar

Keyboard Shortcuts

Shortcut	Action
Enter	Open folder / preview file
Ctrl+A	Select all files
Ctrl+U	Upload files
Delete	Delete selected files / folder / bucket
Backspace	Navigate up one folder level
A–Z	Jump to next file or folder starting with that letter
Mouse Back Button	Navigate back in history
Mouse Forward Button	Navigate forward in history

Update Checker

• Automatically checks for new releases on startup (GitHub API)
• A green "⬆ Update available" label appears in the status bar when a newer version is found
• Click it to open the releases page

Options

Queueing tab

• Max concurrent uploads (1–128, default 3)
• Max concurrent downloads (1–128, default 3)
• Parallel parts per multipart upload (1–128, default 4)
• Multipart upload threshold (5–5120 MB, default 16 MB)

Interface tab

• Dark / Light theme (requires restart)
• Show icon in system tray
• Minimize to system tray
• Bucket pagination page size (100–1000)
• Max file size for preview (1–500 MB)

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Building from Source

Requires .NET 10 SDK.

git clone https://github.com/sibercat/S3Lite.git
cd S3Lite
dotnet publish -c Release -o publish_lite

Output: publish_lite\S3Lite.exe (~4.5 MB, framework-dependent single file)

Tech Stack

• C# / WinForms / .NET 10 — native Windows UI
• AWS SDK for .NET v4 — S3 operations
• Single-file publish — no installer needed