S3UI

A native desktop file manager for Amazon S3 and S3-compatible services.

S3UI is a free, open-source, cross-platform desktop app that makes Amazon S3 feel like a local file system. It provides a dual-pane file manager — local files on the left, S3 on the right — with drag-and-drop transfers, large-file handling, and built-in cost tracking.

Works with Amazon S3, MinIO, and any S3-compatible storage.

Features

• Dual-pane browser — local filesystem and S3 side by side
• Drag and drop — drop files onto the S3 pane to upload
• Upload and download — right-click context menus or drag and drop
• New folder — toolbar button and context menu
• Multipart uploads — large files stream from disk in resumable parts
• Resume support — interrupted transfers pick up where they left off
• Transfer queue — pause, resume, cancel, and retry individual transfers
• Folder operations — recursive downloads and deletion, preserving folder structure
• Copy and rename — server-side copies with metadata preservation
• Share links — copy a presigned download URL
• Bucket-scoped credentials — enter a bucket directly when listing all buckets is restricted
• Cost tracking — estimates your monthly S3 costs as you work
• AWS CLI profiles — auto-discovers profiles from ~/.aws/config
• Custom endpoints — connect to MinIO, LocalStack, or any S3-compatible service
• Secure credentials — stored in your OS keychain via keyring
• Setup wizard — guided first-run configuration
• Keyboard shortcuts — Ctrl+1/2 to switch panes, Ctrl+R to refresh, Ctrl+F to filter
• System notifications — notifies on large transfer completion when the app is in the background

Install

pip install s3ui

Requires Python 3.11+ and a running display server (X11, Wayland, macOS, or Windows).

System requirements

Windows 7 and 8.1 are not supported. S3UI bundles Python 3.12 (Python 3.9+ dropped Windows 7) and is built on Qt 6, which requires Windows 10 or later. On older Windows you'll see Failed to load Python DLL … python312.dll — this is the OS limit, not a corrupt install.

Quick start

s3ui

On first launch, the setup wizard walks you through connecting your AWS account or S3-compatible service. You can also configure connections later from Settings.

MinIO example

In the setup wizard or Settings > Credentials > Add Profile:

Development

git clone https://github.com/justinGrosvenor/s3ui.git
cd s3ui
python -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"
pre-commit install
pytest

To run the release checks without a desktop session:

ruff check src/ tests/ scripts/
ruff format --check src/ tests/ scripts/
QT_QPA_PLATFORM=offscreen pytest
pip install build
python -m build

The repeatable local performance audit is python scripts/audit_hot_paths.py. See the v1.1.0 review for findings, measurements, and the remaining checks on live storage services and platform installers.

License

MIT