Crab Fit

Free, open-source group availability tool that shows a heat-map of when everyone is free.

FreeOpen sourceScheduling and booking tools

Verified facts: 4 of 4
Alternatives ranked: 4
Approved reviews: 0
Visits sent from here: 0

About Crab Fit

Crab Fit is a small, free web app for working out when a group can meet. The organiser picks a range of dates and hours, shares the link, and each person paints the times they're available; the result is a heat-map that makes the best overlap obvious at a glance. Nobody needs an account, and people can enter their availability manually or pull it from their Google or Outlook calendar. It was created by developer Ben Grant as a modern replacement for When2meet-style tools, the code is open source, and the site is funded by donations rather than ads or subscriptions. There is a web version and an Android app. Crab Fit deliberately does one thing: it won't send calendar invites, take bookings or handle payments, so it pairs best with your normal calendar once the group has settled on a time. For hobby groups, students and volunteer teams it is about as simple as scheduling gets.

Best for: Friends, students and volunteer groups finding a time everyone can make.

What works

Completely free with no accounts
Heat-map shows the best overlap instantly
Open-source code

Why people leave

No booking pages or calendar invites
Depends on donations for upkeep
No iOS app

Top Crab Fit alternatives

See all 4

1
Rallly
Open-source date polls with a finalise-and-invite step.
66.5
2
Doodle
The familiar group poll, plus booking pages and sign-up sheets.
62.6
3
zcal
Free booking links with meeting polls for more formal meetings.
59.6
4
Cal.com
Open-source booking pages when you need one-to-one scheduling.
57.2

Why people left Crab Fit

In reviewers' own words, from reviews of the apps they moved to. These are their opinions, not ours.

No switching stories yet. If you moved away from Crab Fit, review the app you switched to and tell us why.

Reviews

No approved reviews yet. How we verify reviewers

Write a review of Crab Fit

Your rating of Crab Fit

Name

Never shown publicly. A work email helps us verify you.

Title

Your review

What did you use it for, and what was good or bad? At least 40 characters.

Did you switch from another app?

Why did you leave it?

How can we verify you use it? (optional)

A GitHub username, your company domain, or say you can send a screenshot. Verified reviews count more.

I received money, credit or a gift for writing this review. (Incentivized reviews are shown but don't count toward rankings.)

By submitting, you confirm you're at least 16 and agree to our terms. Your name, rating, review and the date are published; your email isn't. See our privacy policy.

Crab Fit: common questions

Is Crab Fit free?

Yes, Crab Fit is free to use.

Is Crab Fit open source?

Yes. The source code is on GitHub at GRA0007/crab.fit.

What platforms does Crab Fit run on?

Crab Fit is available for Web and Android.

What are the best alternatives to Crab Fit?

The highest-ranked Crab Fit alternatives right now are Rallly, Doodle and zcal. See the full ranked list for pricing, platforms and verified facts.

See all 4 Crab Fit alternatives

Crab Fit facts

4 of 4 verified

Price: Free, donation-supported; Checked Oct 25, 2026crab.fit(opens source in a new tab); “Consider donating below if it helped you out so Crab Fit can stay free for everyone.”
Open source: Yes; Checked Oct 25, 2026crab.fit(opens source in a new tab); “The code for Crab Fit is open source, if you find any issues or want to contribute, you can visit the repository .”
Creator: Ben Grant; Checked Oct 25, 2026crab.fit(opens source in a new tab); “Watch the video Download the Android app Created by Ben Grant , Crab Fit is the modern-day solution to your group event planning debates.”
Android app: Yes; Checked Oct 25, 2026crab.fit(opens source in a new tab); “Watch the video Download the Android app”