Every challenge below can be played on this timer, and every one of them can be run by hand in Free-form - the plain stopwatch with no target, no scoring, and a cumulative clock. That is how these are played on TikTok: a big countdown timer sits on a table or a stand where everyone can see it, players slap a buzzer button in front of them to start and stop it, the group agrees the rules, and everyone keeps score in their heads. Free-form is that timer.
Several of the challenges also ship as built-in modes. A built-in mode does not unlock anything you could not do manually. What it does is referee: it hides the clock at the right moments, adds the times up, tracks who is out, and calls the winner, so nobody has to argue about it. Each challenge below says how to run it by hand and what the mode does for you.
Closest to the target wins (the classic)
The version most people mean by the Stopwatch Challenge. A target time is set, everyone gets one attempt with the clock hidden, and whoever lands closest takes the round. "Closest to 5 seconds wins" and "stop the timer at 3 seconds" are the common TikTok phrasings, and the winning margin gets brutally small once a group warms up.
By hand: in Free-form, agree a target out loud, take turns, and note each person's time as they go. Use Hide above the recent times list so the next player cannot see what they are chasing.
Built in: Target mode (free) rolls a random target each round, masks the digits while you run, keeps every score hidden until the last player has gone, and crowns the round. Set Best of 3 / 5 / 7 in More Settings to play to an overall winner.
Guess the Time
The other format that dominates TikTok. One person runs a hidden timer and stops it whenever they like, and everyone else guesses how long it ran. Closest guess wins. It plays completely differently to the target game: nobody is testing reflexes, everybody is testing their internal clock.
By hand: in Free-form, the runner starts and stops the clock with the screen turned away, everyone says a number out loud, and then the screen comes back around. Tap Hide first so the running total is not visible when you turn it back.
Built in: Guess the Time mode (free) masks the digits from everyone including the runner, collects each guess in turn, reveals the answer at the end, and rotates the runner so the role moves around the group.
Stop at exactly the number (10.00 is the famous one)
The purist version, and the one behind the viral free pizza challenge. No "closest wins" consolation: you either hit the number or you do not. Ten is the famous one, but the group picks whatever it likes - five, three, one, even half a second - and the shorter the number, the more it stops being counting and starts being pure reflex.
By hand: Free-form, agree the number, and take turns until somebody nails it. Groups usually let a near miss count, which is worth settling before you start rather than after somebody lands on 10.02.
Built in: Exact Time mode (premium) takes one shared target - 1, 3, 5 or 10 seconds, a fresh whole-second Surprise each round, or any number you type from 0.1 to 60 - and turns near misses into stakes. The pot starts at one point and grows by one on every miss, so whoever finally hits it takes the lot. You also choose up front how tight a hit has to be, from dead-on to a forgiving window, which settles the 10.02 argument before it starts.
Ladder
Three rungs, in order: half a second, one second, two seconds. Hit your current rung to climb, miss and you stay where you are. First to clear the top wins. It is the one competitive format that works just as well alone, because you are really racing your own consistency.
By hand: Free-form, call out which rung you are on before you go, and let the group judge the result.
Built in: Ladder mode (premium) tracks each player's rung separately, shows the active player their current target, and tells you whether you were dead on or just close enough. You set how tight "close enough" is, from the brutal display-exact version to something a younger player can land.
Bullseye
Darts, played on a clock. One shared target, and every single turn scores: dead on is worth three, inside the tight ring two, inside the outer ring one. Nobody goes home with nothing, which makes it the friendliest version for mixed ages and the easiest one to keep playing "just one more round" of.
By hand: agree your rings before you start (something like within 0.02 and within 0.05 of the target), then score each attempt out loud in Free-form.
Built in: Bullseye mode (premium) sizes the rings for you against whatever target is in play, banks the points as each person shoots, and names the best shot of the round.
The three below need other people. Everything above works alone as well as in a group.
Don't Go Over
One clock, shared by everybody, running total, and a limit nobody may cross. Each player adds as much time as they dare and passes on. Play safe and you hand the problem to the next person; get greedy and you bust. Landing exactly on the limit is the best play in the game. Two players is enough, and it plays completely differently at two than at six.
By hand: Free-form is built for this one. The clock is cumulative, so STOP pauses and the next START picks up where the last player left off, exactly the way one timer on the table keeps counting as each player takes their turn on the button. Agree a limit, hit Hide so nobody can read the running total, and track it in your heads.
Built in: Don't Go Over mode (premium) keeps the total hidden, judges the bust for you, and reveals the whole turn-by-turn story at the moment somebody goes over, including how close the near misses were. By default the limit re-rolls each round, so a short one plays twitchy and a long one turns into a siege.
Knockout
The target game with teeth. Everyone still aims for the target, but instead of awarding a point to the closest, the furthest away is out. Play it with five people and it takes four rounds to find a winner, and the pressure climbs as the group shrinks.
By hand: play a normal round in Free-form or Target, then whoever is furthest off sits out the next one. Keep going until one person is left.
Built in: Knockout mode (premium) rolls a fresh target each round, keeps every attempt hidden until the reveal, names who is knocked out, and skips eliminated players automatically on the following rounds.
Relay (teams)
A team format you will see on TikTok with three to five players a side. The team picks a total - 15 seconds works for five players, 12 for four, 9 for three - and each member takes a turn aiming at their share, so 3 seconds each for a 15-second team. The team total is everyone's actual times added together, and the closest team to the agreed number wins. It works cooperatively, with one team trying to nail its own total, or head to head with two teams racing and the lowest combined error taking it.
By hand: Free-form's cumulative clock does the adding for you. Start, stop, pass, and the total keeps building across the whole team. Hide the list if you do not want the second team to see what they are chasing.
Built in: nothing yet. Relay is designed but not built, so for now this one is a Free-form game.