Crab.fit

Crab.fit is a free, open-source group scheduling tool that modernizes the availability-grid formula. You name an event, choose specific dates or days of the week and a time range, share the link, and a live heat map fills in as participants add their availability — updating in real time so the best overlap is always visible. More than 196,000 events have been created to date.

It reads as the direct upgrade to When2meet for people who want the same simplicity with a cleaner, more polished interface. Timezone support is extensive, covering regions worldwide so distributed groups see correct local times, and no account is required to create or join an event. Beyond the web app there is an Android app, and the entire codebase is open source on GitHub for anyone who wants to contribute or self-host.

Crab.fit is privacy-minded by default: events are automatically deleted after three months of inactivity and optional passwords are securely hashed. Like the other grid tools, it finds a time for a group rather than managing bookable services or payments. It fits distributed teams, friend groups, and communities that want a fast, attractive, timezone-aware way to settle on a meeting time.