About Tomojoo

Last updated: October 31, 2026.

Tomojoo is the word chain that goes from hand to hand: you change just one letter of the word, send the link to a friend on WhatsApp or Snapchat, and so on. Whoever breaks the chain loses!

From a little solo game to a game with friends

Tomojoo started out as a little solo phone game: change one letter of the word against the clock, CAT → COT → DOT → DOG. Christelle had the idea of turning it into a game for several players, right in the phone’s browser: the word travels like a chain through your conversations, sometimes for days, and everyone tries to build the longest chain they can.

The original solo game is still here, on the play solo page.

How it works

1. Start a game: live, all day in a WhatsApp group, or as a chain with friends, from 3 to 6 letters. The starting word is picked at random.
2. Invite your friends with the link: everyone joins with their name.
3. Take turns, with thirty seconds each to change just one letter of the word.
4. No word, you lose: that player is out, and the last one standing wins. In a chain, whoever breaks the chain loses.

The full rules and some tips are on the how to play page. Ready? Start your first game.

Our principles

• Your chains stay between you: a chain can only be seen by people who have its link, never appears in search engines, and its names are deleted 30 days after it ends. The details are in the privacy policy.
• Free, for real: no account, nothing to buy, nothing to install.
• No fake numbers: no fake chains, no fake records. The site is new, and everything starts from zero.
• Low-key advertising: the site may show ads on the rules, leaderboard and guide pages, only after you agree, and never during a game.

What doesn’t exist yet

The Tomojoo website doesn’t send notifications: the person who plays before you sends you the link. Keep it so you can come back and see how the chain is doing.

Sources and licenses

The dictionary for each language is built specially for Tomojoo: we only keep words of 3 to 6 letters, and we remove swear words and proper names. To build it, we rely on free resources, which we thank:

• Word frequency: lists drawn from the OpenSubtitles 2018 subtitles, the FrequencyWords project by Hermit Dave (CC BY-SA 4.0 license).
• Spelling check: the free Hunspell spell checkers for each language, those of LibreOffice and of the dictionary packages (SCOWL, igerman98, OpenTaal, VERO, sjp.pl, Magyarispell…), under MIT, BSD, GPL, LGPL or MPL licenses depending on the language. Our lists do not copy these files: they only keep words that the files recognize.
• Finnish: list of modern Finnish words from the Institute for the Languages of Finland, Kotus (CC BY 3.0 license).
• Banned words: the LDNOOBW list (CC BY 4.0 license), completed language by language.
• Fonts: Fraunces and Inter, under the SIL Open Font License.

Contact

An idea, a word missing from the dictionary, a problem? Write to contact@prozissimo.com.

This page is a translation; if there is any difference, the French version prevails.