Interval Timer
The short answer: this is a free interval timer — a countdown that rings, resets itself and runs the next round automatically, for as many rounds as you want. Set the length, pick an alarm, press Start, then press Fullscreen for the projector. Every setting fits in a short link you can share or write on the board, such as slidetimerapp.com/r/5.
How to run a station rotation with a repeating timer
The classic use is a room full of question stations: every student works on one question, the alarm rings, everyone shifts one seat along, and the clock starts again. Set it up once and the timer runs the whole activity for you:
- Put one question or task at each station, and decide how long a student should spend on it.
- Open this page on the computer connected to your projector. The timer already opens in Repeat mode.
- Set Each round to that length. Use the min and sec boxes for anything you like — 0 min / 20 sec is a perfectly good round — or tap one of the presets, which start at 10 seconds.
- Set Rounds to the number of stations, so the timer stops by itself when the rotation is complete. Leave it on Unlimited if you would rather end the activity by hand.
- Choose an Alarm sound and press Test once, so you know it carries to the back of the room before the lesson starts.
- Press Start, then Fullscreen. Each time the alarm rings, students move one station along and the next countdown is already running.
Short links you can remember
A timer is only useful in a lesson if you can get back to it in five seconds. Every combination of settings has a short address, so you can type it from memory, put it in a lesson plan or write it on the whiteboard for a colleague:
| Link | What it opens |
|---|---|
slidetimerapp.com/r/5 | 5-minute rounds, repeating until you stop it |
slidetimerapp.com/r/20s | 20-second rounds — add s for seconds |
slidetimerapp.com/r/90s | 90-second rounds (anything from 5 seconds up) |
slidetimerapp.com/r/1m30 | 1 minute 30 seconds per round |
slidetimerapp.com/r/5x8 | 5-minute rounds, 8 rounds, then it stops |
slidetimerapp.com/r/3?a=bell | 3-minute rounds with the school-bell alarm |
slidetimerapp.com/loop/5 | Same as /r/5 — /loop/ is an alias |
The Copy button under the timer always shows the link for whatever you have set right now, so you never have to build one by hand.
Choosing the alarm sound
The sound that ends a round matters more than it sounds like it should: it has to cut through a room of talking students without making anyone jump. Five options are built in, and the one you pick is remembered on that device.
| Alarm | Best for |
|---|---|
| Beep | The default. Three clear tones — the same signal the desktop app uses. |
| Chime | Three falling bell notes. Calm rooms, exams, adult training. |
| School bell | A fast ring. The loudest option, and the one a busy class reacts to fastest. |
| Buzzer | A low, blunt tone. Games, quizzes and drills where you want an obvious buzz. |
| Soft marimba | A short rising phrase. Young children, or when a bell would be too sharp. |
Sound while the clock is running
Time passing silently is easy to lose track of when heads are down. The While running menu adds an optional sound on every second, and it is set to Silent until you choose otherwise:
- Tick — one short click per second, so students hear the time going without looking up.
- Tick-tock — the same, alternating between two pitches, like a wall clock.
- Soft pulse — a low, quiet thump. Noticeable in a quiet room, easy to ignore while writing.
- Ambient hum — a slow, breathing chord instead of a beat. It fills the silence of a written test without giving anyone a rhythm to rush to.
Interval timer or plain countdown?
Both live in the same widget — the mode row at the top switches between them. Use this to pick:
| What you need | Countdown | Repeat |
|---|---|---|
| One block of time, then it stops | Yes | No |
| The same block, again and again | No | Yes |
| Rings at the end | Yes | Yes — every round |
| Counts the rounds for you | No | Yes |
| Stops itself after a set number of rounds | No | Yes |
Want the repeating timer on top of your slides?
A browser tab cannot sit on top of a full-screen Slide Show. SlideTimerApp floats a transparent countdown with a red warning and an alarm over PowerPoint, Google Slides or Canva — free for Windows — so the question stays on the slide while the time stays visible.
Download SlideTimerApp free ~3 MB · Windows · works offlineWhere a repeating timer earns its place
- Question stations: one question per desk, one round per question, students shift on the alarm. The timer runs the whole rotation without you calling time.
- Oral tests and interviews: a fixed slot per student, with an audible end that nobody can argue with.
- Speaking and language practice: pairs talk for two minutes, swap partners on the bell, repeat.
- Drills and PE: equal work intervals with the same signal every time.
- Focus blocks: for the 25-minutes-on, 5-minutes-off pattern specifically, the Pomodoro timer is already set up for you.
- Music and skills practice: rotate through exercises without stopping to reset a clock.
For everyday lesson timing that does not need to repeat, see the classroom timer; for a single timed assessment, the exam timer is the simpler tool.
More timers
Classroom timer
A big, visible countdown for lessons and activities.
Exam timer
Fullscreen countdown with an alarm, for tests and quizzes.
Fullscreen timer
When the timer itself is the screen.
Frequently asked questions
What is an interval timer?
An interval timer is a countdown that repeats. It counts down from the length you set, sounds an alarm when it reaches zero, then resets and starts the next round on its own, without anyone pressing a button. That makes it the right tool whenever the same block of time has to happen over and over: rotating students between question stations, running drills, or timing repeated practice turns.
How do I make a timer repeat automatically?
Use the timer at the top of this page. Press Repeat in the mode row, set how long one round should last, choose how many rounds you want (or leave it on Unlimited), then press Start. At zero it rings, holds on 00:00 for one second so everyone hears the signal and moves, then counts down again from the full time.
Can I choose the alarm sound?
Yes. There are five alarm sounds: Beep, Chime, School bell, Buzzer and Soft marimba. Pick one from the Alarm sound menu and press Test to hear it before the lesson starts. Your choice is remembered in the browser, so the same sound is used the next time you open the page on that device.
Does the timer make a sound while it is running?
Only if you want it to. The While running menu offers Silent, Tick, Tick-tock, Soft pulse and Ambient hum. Silent is the default. A quiet tick makes the passing time audible for students who are not looking at the screen, and the ambient hum gives the room a calm background tone during written work.
Can I share a link to a timer that is already set?
Yes, and the link is short enough to write on a whiteboard. slidetimerapp.com/r/5 opens a five-minute repeating timer, slidetimerapp.com/r/5x8 runs five minutes for eight rounds, and slidetimerapp.com/r/90s uses ninety-second rounds. Press Copy under the timer to get the link for your current settings.
How do I use an interval timer for classroom stations?
Put one question or task at each station, set the round to the time you want students to spend on one question, and set the number of rounds to the number of stations. Open the timer on the projector and press Fullscreen. Every time the alarm rings, students move one station along, and the countdown for the next question has already started.
Can I keep a repeating timer on top of my slides?
A browser tab cannot stay on top of a full-screen slideshow. Download SlideTimerApp, a free Windows overlay that floats a transparent countdown over PowerPoint, Google Slides or Canva and rings an alarm at zero, so you can show the question on the slide and the time remaining at the same time.