AlgoArena Privacy Policy

AlgoArena is a Chrome extension that adds a collaborative panel on leetcode.com so people in a room can chat, talk, and share a drawing while solving a problem. This page describes what data the extension handles.

Who we are

AlgoArena is an open-source project: github.com/CodingRI/AlgoArena. Questions: open a GitHub issue.

What we collect

The extension and its backend process only what is needed to run a room:

• Display name you choose in the panel (default: “Anonymous”).
• Generated user id stored in your browser so you can rejoin a room.
• Room data — room name, language, membership, join requests.
• Chat messages sent while you are in a room.
• Shared canvas / laser-pointer data during explanation mode.
• Voice — microphone audio only while you turn voice on. Audio is sent peer-to-peer (WebRTC). Signaling (who is in the call) goes through our server. We use public STUN servers at stun.l.google.com so browsers can connect.
• Settings such as notification and appearance toggles, stored locally in your browser.

We do not create accounts, do not require email, and do not use analytics, advertising, or tracking pixels.

Where data goes

Collaboration traffic is sent to our backend at algoarena-rc9v.onrender.com over HTTPS and WSS. Rooms are stored in memory only on that server. They disappear if the process restarts, redeploys, or sleeps. Chat, canvas, and room membership are not written to a database.

The extension injects a panel into LeetCode pages. It does not scrape problem statements, solutions, or your editor code to send to our server.

What stays on your device

Display name, user id, last room id, known rooms, and settings are saved in localStorage and/or chrome.storage.local on your computer. Uninstalling the extension removes that data.

Permissions

• storage — save settings locally.
• Host access to leetcode.com / leetcode.cn — show the panel on those sites.
• Host access to algoarena-rc9v.onrender.com — REST API and WebSocket.

The microphone is requested by the browser only when you enable voice, and only for the LeetCode tab you are on.

Sharing and selling

We do not sell personal data. We do not share it with advertisers. Other people in the same room can see your display name, chat, canvas strokes, and hear you if you unmute.

How to delete your data

• Leave the room from the panel header.
• The room host can close the room, which drops it from the server.
• Uninstall AlgoArena to clear local settings and ids.

Children

AlgoArena is not directed at children under 13.

Changes

If this policy changes in a material way, we will update the date at the top of this page.