featherdrop is a sleek, feather-light, self-hosted drop zone for your files — think WeTransfer or Smash, but it runs on your own server with no size paywall. Drop your files (one or a whole batch), set how long they live (plus an optional password or download limit), and share a short link or QR code. Zero-knowledge end-to-end encryption, resumable uploads, inline previews, one tiny container. No accounts, no clouds, no tracking, no nonsense.

Table of Contents

1. What is this?
2. Screenshots
3. How it works
4. Security & Privacy
5. Languages
6. Quick Start on Unraid
7. Configuration
8. Reverse Proxy
9. Local Development
10. Contributing / License
11. License
12. Support this project

1. What is this?

featherdrop is a sleek, feather-light, self-hosted file-sharing page for your own server — your own private WeTransfer, minus the accounts, size paywalls, and handing your files to someone else's cloud. It's a much simpler take inspired by Pingvin Share. Where Pingvin ships a full backend, database, and accounts, featherdrop is a single container with no login and no separate database:

• Open the page → a central drop zone is right there.
• Drop a file — or several at once, or just Ctrl+V a screenshot → a settings panel slides in (expiry, optional password, optional download limit), and a progress ring overlays the drop zone while it uploads.
• You get a shareable link plus a QR code you can save as a PNG. The recipient can preview the files right on the share page and download them any time until the share expires.
• Pasting the link into a chat shows a clean preview card — your branding, never the file's name.
• A light/dark toggle and a flag language picker sit in the header — the UI speaks 26 languages and picks yours from the browser.

What it deliberately does not have: user accounts, OIDC/LDAP, email, malware scanning, S3 backends. If you need those, use Pingvin Share — that is the point.

2. Screenshots

The home page — drop a file to share it.

Light and dark themes, with a flag language picker.

Set an expiry, an optional password, and a download limit before sharing.

Your link is ready — copy it or save the QR code.

What the recipient sees: file info and a download button.

3. How it works

Browser (drop zone, Mantine UI)
   │  resumable upload (tus)
   ▼
featherdrop container (single static Go binary, embedded React/Vite SPA)
   ├─ /files            tus upload endpoint
   ├─ /api/finalize     move file into store, write metadata, mint share slug
   ├─ /d/<slug>         share page (info, password gate, download)
   └─ cleanup job       deletes expired files
   ▼
/data volume (uploads, bulk)        /config volume (metadata, small)
   ├─ uploads/<id>   the files          └─ db.sqlite   (pure-Go SQLite — a file, not a server)
   └─ tmp/<id>       in-progress uploads

/data (bulk files) and /config (the small SQLite database) are separate volumes, so you can keep uploads on array storage and the database on a fast SSD. CONFIG_DIR defaults to DATA_DIR, so a single-volume setup still works.

Uploads are resumable: a dropped connection on a multi-GB transfer resumes instead of starting over. Share passwords never reach the server at all — the key is derived from them in your browser (Argon2id) — and large downloads stream natively (no in-browser buffering). The container ships a built-in healthcheck (the binary probes its own /api/healthcheck — distroless has no shell), so Docker and Unraid show a real health state.

4. Security & Privacy

featherdrop is built to be self-hosted: your files and their metadata live only on your server, and the app talks to nobody else.

• No accounts, no tracking. No sign-up, no analytics, no telemetry, and no third-party scripts or fonts pulled at runtime — nothing phones home.
• Your data stays yours. Uploads sit on your /data volume, metadata in a local SQLite file. Nothing is ever sent to a cloud or external service.
• Zero-knowledge by design — every file is end-to-end encrypted in your browser before upload; the filename and type are encrypted inside the blob, so the server (and any stolen disk or backup) sees only opaque ciphertext, never your files or their names (details below).
• The operator can't read your files either. The key never reaches the server — it lives in the link's #fragment, or is derived from your password.
• Self-destructing. Every share has an expiry (down to 1 hour), and an optional download limit burns the file the moment it's reached — shares are removed automatically, no manual cleanup needed.
• Minimal attack surface. No login to brute-force, no user database to leak; share slugs are unguessable, and share pages and link previews never expose the file's name. Uploads and download/password attempts are rate-limited per IP out of the box, and share pages tell search engines to stay away (robots.txt plus X-Robots-Tag: noindex on every share response).
• Photos travel light. JPEGs can be scrubbed of EXIF/GPS/IPTC metadata — in the browser, before encryption, the only place it can happen (on by default, one switch to keep it).
• Hardened supply chain. The image is a single static Go binary on a distroless base — no shell, no package manager, digest-pinned — and every build ships SBOM + provenance attestations and gets a Trivy CVE scan in CI.

Provided under the AGPL-3.0 licence without warranty — you run it, you own the data and the responsibility. HTTPS is recommended (see Reverse Proxy) — the clipboard, streaming downloads, and large (>500 MB) uploads need a secure context; smaller uploads work over plain HTTP too.

Zero-knowledge encryption

Every file is encrypted in your browser before it is uploaded, with libsodium's XChaCha20-Poly1305 streaming AEAD (64 KiB chunks). The original filename and content type are encrypted inside the blob, so the server only ever stores — and serves back — opaque ciphertext and its length. It performs no cryptography and never receives the key.

The content key never reaches the server. Where it lives depends on the share type:

Because the link key lives in the URL fragment (#k=…), it is never sent in an HTTP request and never appears in server logs or your reverse proxy. Treat the whole link as the secret: anyone who has it can download the file until it expires, and a link copied without its #k=… part can't be decrypted — by design, since the server never had the key.

Downloads also require proof of key knowledge: the browser sends a one-way SHA-256 verifier of the content key (x-fd-key-verifier header), so someone who only saw the slug in a proxy or access log can't burn through a share's download limit — without the verifier (which reveals nothing about the key), nothing is counted and nothing is deleted. Shares uploaded before this check existed keep working unchanged.

Encryption and decryption stream through the Origin Private File System and a service worker, so multi-GB files are never buffered in memory. Over plain HTTP (not a secure context) OPFS isn't available, so encryption falls back to memory with a 500 MB cap — use HTTPS for larger files. Inline image/PDF previews are produced entirely in the browser from the decrypted bytes.

Still have pre-v4 shares? Shares created before v4 used server-side at-rest encryption (age). Since the v6 Go rewrite the server is zero-knowledge only and no longer serves that legacy format — those links return 404, and the old MASTER_KEY / ENCRYPT_UPLOADS settings are ignored.

5. Languages

featherdrop's interface ships in 26 languages. On a visitor's first load the language is taken from their browser; a flag picker beside the light/dark toggle (in the header and on the download page) switches it, and the choice is remembered. Detection happens right in the browser before the first paint, so there is no English flash. Arabic and Hebrew render right-to-left.

🇬🇧 English · 🇩🇪 Deutsch · 🇫🇷 Français · 🇪🇸 Español · 🇮🇹 Italiano · 🇵🇹 Português · 🇳🇱 Nederlands · 🇵🇱 Polski · 🇷🇺 Русский · 🇺🇦 Українська · 🇨🇿 Čeština · 🇸🇪 Svenska · 🇩🇰 Dansk · 🇫🇮 Suomi · 🇳🇴 Norsk · 🇹🇷 Türkçe · 🇬🇷 Ελληνικά · 🇭🇺 Magyar · 🇷🇴 Română · 🇯🇵 日本語 · 🇰🇷 한국어 · 🇨🇳 中文 · 🇸🇦 العربية · 🇮🇱 עברית · 🇹🇭 ไทย · 🇻🇳 Tiếng Việt

Each language is a typed file under lib/i18n/locales/, with English as the source of truth. A native-speaker correction is a one-file edit — pull requests welcome.

6. Quick Start on Unraid

Pull the template into Unraid via the console / SSH:

mkdir -p /boot/config/plugins/dockerMan/templates-user && \
curl -fsSL -o /boot/config/plugins/dockerMan/templates-user/my-featherdrop.xml \
  https://raw.githubusercontent.com/junkerderprovinz/unraid-apps/main/featherdrop/featherdrop.xml

Then Docker → Add Container → featherdrop under User templates. Map the Data Directory (uploads) and Config Directory (the database) to your appdata, pick a port, hit Apply, open the WebUI.

The template filename must keep the my- prefix (my-featherdrop.xml) so Unraid treats it as a user template.

Plain Docker (no Unraid)

docker run -d \
  --name featherdrop \
  --restart unless-stopped \
  -p 3000:3000 \
  -e BASE_URL=https://share.yourdomain.tld \
  -e CONFIG_DIR=/config \
  -v /mnt/user/appdata/featherdrop/data:/data \
  -v /mnt/user/appdata/featherdrop/config:/config \
  junkerderprovinz/featherdrop:latest

To keep everything on a single volume instead, drop the CONFIG_DIR line and the /config mount and map just -v …:/data — the database then lives in /data alongside the uploads.

7. Configuration

8. Reverse Proxy

featherdrop speaks plain HTTP on PORT; put TLS in front of it (Nginx Proxy Manager, Caddy, Traefik). Two things matter:

• Set BASE_URL to your public URL so generated links are correct. Use HTTPS — for link shares the decryption key lives in the URL fragment, and TLS keeps the whole link private in transit. HTTPS is also a secure context, which the clipboard, streaming downloads, and OPFS (large uploads) require; over plain HTTP, uploads fall back to an in-memory path capped at 500 MB.
• Allow large request bodies and generous timeouts for big uploads. For Nginx / NPM advanced config:

client_max_body_size 0;        # no cap here (but a CDN may add one — see below)
proxy_read_timeout 3600s;
proxy_send_timeout 3600s;
proxy_request_buffering off;   # stream uploads straight through

Uploads are sent in resumable 64 MiB chunks (tus), so each request stays small no matter the file size, and a dropped upload resumes from the last chunk.

Behind Cloudflare or another CDN: a proxying CDN enforces its own request-body limit before your reverse proxy, so client_max_body_size 0 cannot override it. Cloudflare's Free and Pro plans cap a request body at 100 MB (Business 200 MB, Enterprise 500 MB) and return 413 above it. Because featherdrop chunks at 64 MiB, files of any size still upload through Cloudflare — but if you raise chunkSize (in app/page.tsx) above the cap, or front featherdrop with another capped proxy, large uploads will 413.

Remote-access options (all keep split-horizon DNS — resolve the host to your LAN reverse proxy internally and to the public edge externally):

9. Local Development

npm install
npm run dev          # Vite dev server for the React SPA (http://localhost:5173)

Build the static SPA and run it the way the container does — the Go backend serves the embedded SPA plus the JSON/file API on port 3000:

npm run build:spa            # build the Vite SPA into server-go/webroot
cd server-go && go run .     # serve on http://localhost:3000, data under ./data

Run the test suite (pure-logic assertions, no framework needed):

npm test

Stack: a Go backend (server-go/) that serves a Vite + React + Mantine SPA as embedded static assets alongside the JSON/file API, with react-i18next for the UI languages. The browser keeps all zero-knowledge crypto in TypeScript (libsodium). Files live under DATA_DIR (default ./data). The published image is built from Dockerfile — a three-stage build: Vite SPA → static Go binary with the webroot embedded → distroless runtime. The old Next.js server was retired in v6.0.0; the Go backend is the only server.

10. Contributing / License

Issues and pull requests welcome: https://github.com/junkerderprovinz/featherdrop/issues

Licensed under the GNU Affero General Public License v3.0 (AGPL-3.0); see section 11.

11. License

Copyright (C) 2026 Junker der Provinz.

featherdrop is free software under the GNU Affero General Public License v3.0 (AGPL-3.0); see LICENSE. You may run, study, share and modify it. If you distribute it, or run a modified version as a network service, you must release your source under the same AGPL-3.0 terms and keep the existing copyright and attribution notices intact.

Name and branding are not licensed. The AGPL covers the source code only. "featherdrop", its logo and its branding remain reserved: a fork or derivative must use its own distinct name and branding, and may not present itself as featherdrop. This keeps it unambiguous which project is the original.

12. Support this project

If featherdrop saves you a trip to a third-party file host, consider buying me a coffee: