Free Online Stopwatch with Laps and HIIT

What a free online stopwatch is for

An online stopwatch counts up from zero so you can measure how long something takes—runs, drills, lab trials, speeches, or gym intervals. Tap the face, press Start, or hit Space, then mark laps for each split without installing an app.

Open the free online stopwatch for the full board, or jump to a preset landing when you already know the session type: lap timer, HIIT stopwatch, or swim stopwatch. Timing stays accurate in a background tab and private on this device—no account.

How to time laps in under a minute

1. Open a stopwatch page. Use the main stopwatch or the lap timer landing if you want sport face, arm countdown, and lap sounds pre-applied.
2. Arm if you need it. Optional 0 / 3 / 5 / 10 second arms give you a clean “go” after the beep.
3. Start, then Lap. Mark each split. Best, average, and worst update under the board; the stage keeps recent laps and a current-lap pace cue.
4. Finish cleanly. Stop when the set ends, then copy or export CSV from the toolbar.

Lap timer, HIIT, and swim presets

• Lap timer. Track-focused preset: sport skin, five-second arm, lap sounds. Built for runs, drills, and practice sets where splits matter.
• HIIT stopwatch. Midnight sport look and a ten-second arm. You still control work/rest with Start and Lap—ideal when the floor is messy and fixed auto-rounds would fight you.
• Swim stopwatch. Three named timers (warmup / main / cooldown) so pool sets switch without resetting the whole board.

Need automatic round lengths (Tabata-style)? Pair with an online countdown timer for fixed intervals, and keep the stopwatch for elapsed cues you mark by hand.

Multi-timers, display mode, and export

The hub supports up to three named timers side by side—useful for parallel athletes or set phases. Display mode (or fullscreen) keeps digits readable across a gym or classroom. When the session ends, export or copy CSV so splits leave with you; history stays local on the device.

Stopwatch vs timer vs chess clock

A countdown timer runs for a fixed duration from now—class periods, exams, cooking. A stopwatch measures elapsed time and laps. An over-the-board chess clock alternates two opposing clocks after each move—not a training stopwatch. Pick the tool that matches the rule you are enforcing.

Tips so sessions stay usable

• Unlock sound with the first tap if you rely on arm or lap beeps—some mobile browsers stay muted until then.
• Keep the tab available for audio; elapsed math still stays honest if the tab is throttled.
• Prefer hundredths by default; turn on milliseconds only when the activity needs them (lab, speech).
• Do not expect auto work/rest switching on HIIT—mark intervals yourself or use a countdown timer for fixed rounds.

Open the free stopwatch

Start on the online stopwatch, or open lap timer / HIIT when you want a preset face. Press Start, mark laps, export when you are done—no install, no account.