QuackThink is a free online platform for multiplayer trivia and party games, designed to bring friends together for quick browser-based sessions. Players can create or join a lobby using a shared link, with no downloads or sign-ups required. The host can choose game modes, start matches, set category filters, round limits and turn timers, and manage players by assigning moderators or removing participants.

The available games include Millionaire Quiz, where players answer questions and use special jokers; Image Guess, which challenges them to identify pictures as they gradually come into focus; and Order It, where they rank items by hidden statistics. Guess the Price awards points for estimating product prices, while Stay in Budget asks players to select items without exceeding a spending limit. Across a session, overall points determine the champion. QuackThink also offers lobby settings, player invitations, language and volume controls, and leaderboards between rounds. The site includes articles about ducks and invites players to share feedback, report bugs, and suggest ideas for future games.