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Lightspeak is a small, private alternative to Discord and TeamSpeak. You run the server yourself – on a cheap VPS, a Raspberry Pi or an old PC – and invite your friends with a link. There is no central service, no account with a company, no tracking and no ads.

It was built around one idea: a chat app should not need a gigabyte of RAM. The Windows app is a few megabytes, starts in under a second and stays out of the way while you play.

Highlights

• 🎙️ Voice channels that just work – Opus audio, noise suppression, echo cancellation, per-user volume, and global push-to-talk (keyboard or mouse buttons) that also works in full-screen games.
• 🖥️ Screen sharing up to 1440p / 60 fps – hardware-encoded H.264, with the sound of just the shared app or the whole system (without your friends' voices echoing back).
• 🔒 End-to-end encrypted calls – voice, screen and stream audio are encrypted on your devices. The server only forwards data it cannot decrypt.
• 💬 Text chat – spaces, channels and categories, direct messages and group chats, replies, reactions, pins, mentions, Markdown with syntax highlighting, full-text search and files up to 200 MB.
• 🛡️ Roles and permissions – per-space roles, per-channel overrides, private channels, announcement channels, stage-style voice channels, an away channel and slow mode.
• 🪶 Lightweight – see the numbers below. What you don't use costs nothing: video is only received while you watch, and the app trims its memory when it sits in the tray.
• 🌍 No install needed for guests – the same client runs in Chrome, Edge, Firefox and Safari (also on macOS and Linux), served by your own server.
• 🧰 One-command server – a single installer sets up the server, LiveKit and HTTPS certificates as systemd services. No Docker, about 250 MB of RAM in total.
• 🇬🇧 🇩🇪 English and German, light and dark theme, accent colours.

Light theme	Voice settings

How light is it?

Measured on Windows 11 with the release build (whole process tree, including WebView2):

	Lightspeak	Discord (for comparison)
Window open, idle	80–150 MB	~1,080 MB
Minimised to the tray	~70 MB	–
In a voice channel	~150 MB	–
Idle CPU	~0.1 %	~0.6 %
Installer	~2 MB	–
Cold start until usable	~0.4 s	–

The server side (Lightspeak server + LiveKit + Caddy) idles at roughly 250 MB of RAM on a small VPS.

How is that possible?

• The app is built with Tauri: it uses the WebView2 runtime that Windows already ships instead of bundling its own browser.
• The interface is plain Svelte with hand-written CSS – no UI framework, about 125 KB of JavaScript (gzip) at start. Everything else is loaded on demand.
• Message lists are virtualised, images are loaded as server-side thumbnails, and video tracks are only subscribed while a stream is actually on screen.
• Native parts (push-to-talk hook, per-app audio capture, encryption keys) are written in Rust and only run while they are needed.

Quick start

I just want to join my friends' server

1. Open the invite link you received.
2. Click Download Lightspeak for Windows and run Lightspeak-setup.exe (no admin rights needed) – or pick Open in browser to skip the install.
3. Choose a username and a password. Done.

Windows may show "Windows protected your PC" because the installer is not commercially code-signed. Click More info → Run anyway. You can verify the download against SHA256SUMS on the releases page.

More in the user guide.

I want to host a server

You need a Linux machine (Debian 12+ or Ubuntu 22.04+, x86_64 or arm64, 1 vCPU / 1 GB RAM is enough) with a public IPv4 address and two host names pointing at it – your own domain or free sslip.io names.

curl -fsSLO https://github.com/syntstar/lightspeak/releases/latest/download/install.sh
sudo bash install.sh --version latest

The installer asks a few questions, shows what it is going to do and only then changes anything. At the end it prints an owner invite link: open it, create your account, and you are the admin of your new server. Invite your friends from the app.

Where	Good for	Notes
VPS (recommended)	Always on, fast upload	Any small plan works, from about €4 per month
Home server (Raspberry Pi, NAS, old PC)	No monthly cost	Needs a public IPv4 address and port forwarding
Local	Trying it out, development	One PC only, no HTTPS

The full walkthrough – ports, firewalls, settings, backups and updates – is in docs/SELF_HOSTING.md.

Updating later is one command, with a database backup and an automatic rollback if anything fails:

sudo lightspeak-admin update

The Windows app updates itself from the GitHub releases of this repository. Every update is signed, and the app only installs builds that carry a valid signature.

Documentation

User guide	Installing, talking, push-to-talk, sharing your screen
Self-hosting	Setting up a server on a VPS, at home or locally; settings, backups, updates
Admin guide	Roles, invites, moderation, accounts, storage, troubleshooting
Security	Threat model, encryption, what the server can and cannot see
Architecture	How the pieces fit together
Contributing	Building from source, tests, conventions

Security and privacy

• Calls and screen shares are end-to-end encrypted. Keys are created on your devices and never reach the server unencrypted. If encryption cannot be established, the call does not start – there is no unencrypted fallback.
• Text messages and files are not end-to-end encrypted. They travel over TLS and are stored on your server, so whoever runs the server can read them – the same trust model as Discord, except that the server is yours.
• Passwords are hashed with Argon2id. The Windows app keeps its session and keys in the Windows Credential Manager.
• Server and app releases are signed; the installer and the updater reject anything without a valid signature.

Details and the full threat model: docs/SECURITY.md. Found a vulnerability? Please report it privately – see the security policy.

What Lightspeak deliberately does not do

• Webcam video – the focus is on voice and screen sharing.
• Native macOS, Linux or mobile apps – the desktop app is Windows-only; everything else uses the browser client.
• A Docker image – the installer sets everything up natively, which keeps memory use low.
• End-to-end encryption for text and files – only calls and screen shares are end-to-end encrypted.
• Password reset by e-mail – Lightspeak never asks for an e-mail address. A server admin sets a temporary password instead.
• Federation or public server discovery – a server is for a group of people who know each other.

Building from source

# Server (Go)
cd server
go run ./cmd/lightspeak-server serve --dev

# Windows app (Node.js + Rust)
cd client
npm install
npm run tauri dev

Prerequisites, tests and the release process are described in CONTRIBUTING.md.

Built with

Tauri · Svelte · LiveKit · Go · SQLite · Caddy – the complete list with licences is in docs/THIRD_PARTY.md.

License

Lightspeak is free software, released under the GNU Affero General Public License v3.0.

In short: you may use, study, change and share it. If you run a modified server for other people, you have to make your changes available to them under the same licence.