Free Online Stopwatch
Our free online stopwatch lets you accurately time any activity with millisecond precision. Whether you're timing a race, workout intervals, cooking, or any other activity, simply click Start and watch the time count up. Record lap times, split times, and track your progress - all without downloading anything.
How to Use the Stopwatch
Using our stopwatch is simple: Click Start to begin timing. The display shows hours, minutes, seconds, and hundredths of a second. Click Lap to record a lap time while the stopwatch continues running. Click Stop to pause, and Reset to return to zero and clear all lap times.
Popular Uses for a Stopwatch
- Sports and athletics - Time sprints, laps, intervals, and races
- Workout intervals - Track rest periods and exercise durations
- Cooking - Time recipes when you don't have a specific duration
- Games and competitions - Time challenges and speed runs
- Science experiments - Measure reaction times and durations
- Productivity - Track how long tasks actually take
- Music practice - Time song lengths and practice sessions
- Public speaking - Monitor speech and presentation lengths
Stopwatch Features
- Millisecond precision: Displays hundredths of a second
- Lap times: Record multiple laps with split and total times
- Visual display: Analog and digital views
- Start/Stop/Reset: Full control over your timing
- Works on all devices: Phone, tablet, laptop, or desktop
- No download required: Works directly in your browser
Stopwatch vs Timer
A stopwatch counts UP from zero - you use it to measure how long something takes when you don't know the duration in advance. A timer counts DOWN from a set time - you use it when you want to limit an activity to a specific duration. Need a countdown? Try our countdown timer.
Stopwatch for Running & Track
Runners and track athletes rely on stopwatch lap timing to measure splits and improve performance. Whether you're running 400-meter repeats, timing a mile, or tracking a 5K race, recording lap splits helps you understand your pacing and identify where you're gaining or losing time.
- 400m split timing: Track your lap times on a standard 400m track to maintain even pacing
- Mile repeats: Record each mile split during tempo runs or race simulations
- Negative splits: Use lap times to practice running the second half faster than the first
- Interval training: Time your work intervals and rest periods during speed workouts
- Race pacing: Review split times to develop better race strategies
Stopwatch for Swimming
Swimming lap timers are essential for pool training. Swimmers use stopwatches to time lengths, track stroke counts, and measure improvement. Whether you're training for competition or fitness, recording your swim times helps you build endurance and speed.
- Pool length timing: Time 25m or 50m lengths to track your pace per 100m
- Stroke counting: Combine lap timing with stroke counting to measure efficiency
- Rest intervals: Time your rest periods between sets for consistent training
- Personal bests: Record and compare times to track improvement over weeks and months
Rubik's Cube & Speedcubing Timer
Speedcubers use precision stopwatches to time their Rubik's Cube solves. While dedicated cube timers offer scramble generators and WCA-compliant features, a standard online stopwatch works perfectly for casual practice. The goal is to solve the cube as fast as possible, typically using the CFOP or Roux method.
- Sub-20 practice: Work toward solving in under 20 seconds
- Average of 5 (Ao5): Record multiple solves and calculate your average, dropping the best and worst
- One-handed solving: Time OH solves separately from two-handed
- Blindfolded solving: Time memorization and execution phases separately
For serious speedcubing practice, pair this stopwatch with a scramble generator to simulate competition conditions.
Speedrun Gaming Timer
Video game speedrunners use stopwatches and split timers to track their progress through games. While dedicated speedrun software like LiveSplit offers segment comparisons, a simple online stopwatch works great for practice runs and learning routes.
- Single-segment runs: Time complete playthroughs from start to finish
- Individual level (IL) times: Record your best time on specific levels or sections
- Boss fight timing: Measure how long boss encounters take to optimize strategies
- Route optimization: Compare times with different routing choices
Debate and Speech Timing
Speech timers help speakers stay within time limits during presentations, debates, and public speaking events. Toastmasters clubs, debate teams, and conference presenters all rely on accurate timing to deliver effective speeches.
- Toastmasters speeches: Time 5-7 minute speeches with green (5 min), yellow (6 min), red (7 min) signals
- Lincoln-Douglas debate: 6-minute constructive, 3-minute cross-examination, 4-minute rebuttal
- Policy debate: 8-minute constructive, 3-minute cross-ex, 5-minute rebuttal
- TED-style talks: Practice hitting the 18-minute sweet spot
- Elevator pitches: Perfect your 30-second to 2-minute pitch
Science & Lab Experiments
Laboratory timing requires precision for reproducible results. Scientists use stopwatches to measure reaction times, incubation periods, and process durations. While this online stopwatch displays centiseconds, most lab applications need only second-level accuracy.
- Reaction timing: Measure how long chemical reactions take to complete
- Incubation periods: Time samples during experimental procedures
- Human reaction time: Test reflexes and response speeds (average: 200-250ms)
- Physics experiments: Measure motion, pendulum swings, and free fall
Interval Training with Stopwatch
Unlike countdown timers, a stopwatch lets you track open-ended interval training where you push until failure rather than stopping at a preset time. This is ideal for AMRAP (As Many Reps As Possible) and EMOM (Every Minute On the Minute) workouts.
- AMRAP workouts: Start the stopwatch and see how many rounds you complete before you need to stop
- EMOM tracking: Watch the minutes tick over and start each set on the minute
- Rest-pause sets: Time your rest periods between mini-sets
- Plank holds: See how long you can maintain position and beat your previous time
For structured intervals with preset durations, try our workout timer instead.
Time Tracking for Work
Freelancers, consultants, and remote workers use stopwatch time tracking to log billable hours accurately. Unlike complex time tracking software, a simple stopwatch provides instant, honest measurement of how long tasks actually take.
- Client billing: Track exact time spent on projects for accurate invoicing
- Task estimation: Measure how long tasks take to improve future estimates
- Deep work sessions: Time focused work blocks to understand your productive capacity
- Meeting timing: Keep meetings on track by monitoring elapsed time
Understanding Split Time vs Lap Time
Split time and lap time are often confused but measure different things:
- Lap time (split): The duration of the current segment - time since your last lap marker
- Cumulative time (total): The total elapsed time since you started the stopwatch
For example, if you're running a 5K and hit lap at each kilometer: your lap times might be 5:00, 5:15, 5:30, 5:20, 5:10 - but your cumulative splits would be 5:00, 10:15, 15:45, 21:05, 26:15. Both are useful for analyzing performance.
Analyzing Best and Average Lap Times
Recording multiple laps reveals patterns in your performance. Look for your best lap (fastest segment), worst lap (slowest segment), and average lap time to understand consistency and pacing.
- Consistency check: Large variations between laps indicate pacing problems
- Fatigue patterns: Slower later laps suggest endurance issues
- Warm-up effect: Faster laps after initial segments indicate proper warm-up helps
- Peak performance: Your best lap shows what you're capable of at full effort
Stopwatch for Swimming and Pool Training
Swimming stopwatches track lap times, splits, and overall workout duration in the pool. Our swim stopwatch helps swimmers and coaches measure performance precisely.
Pool Training Applications
- Lap splits: Record each 25m or 50m segment
- Stroke counting: Time per stroke cycle for efficiency analysis
- Rest intervals: Track recovery time between sets
- Turn timing: Measure flip turn and push-off speed
- Race simulation: Practice events at competition pace
Analyzing Swim Performance
Compare your first 50m split to your last to measure endurance. Consistent splits indicate good pacing, while large variations suggest technique breakdown from fatigue. Track times over weeks to see improvement. For interval sets with rest periods, combine with our workout timer.
Stopwatch for Cooking and Recipes
Cooking stopwatches track elapsed time for recipes where duration matters but exact minutes aren't specified. Our kitchen stopwatch answers "how long has this been cooking?"
Culinary Timing Uses
- Searing meat: Track minutes per side without preset
- Caramelization: Monitor browning time for sauces
- Bread rising: Record how long dough takes to double
- Marinating: Track total time proteins soak
- Recipe development: Document cooking times for new dishes
Creating Better Recipes
When developing recipes, use the stopwatch to record exact times that work. "Cook until golden brown" becomes "cook for 4 minutes 30 seconds" when you document results. For preset cooking durations, see our cooking timer and egg timer.
Stopwatch for Science and Experiments
Scientific stopwatches provide precise timing for experiments, observations, and data collection. Our lab stopwatch supports research and educational experiments.
Laboratory Applications
- Reaction timing: Measure how long chemical reactions take
- Physics experiments: Time falling objects, pendulums, motion
- Biology observations: Track animal behavior durations
- Astronomy: Time celestial events and transits
- Student labs: Record experiment data accurately
Data Collection Best Practices
For scientific accuracy, use the lap function to record multiple trials without resetting. This captures all data points in one session. Our stopwatch displays milliseconds for precise measurement. Record results immediately—memory is unreliable for exact times.
Stopwatch for Speedcubing and Puzzles
Speedcubing timers measure solve times for Rubik's cubes and other twisty puzzles. Our cube timer tracks your progress toward faster solves.
Puzzle Timing Features
- Single solves: Time individual attempts for PB tracking
- Average of 5: Record 5 consecutive solves for competition format
- Average of 12: Larger sample for consistent measurement
- Inspection time: Use 15-second countdown before starting
- Multiple puzzle types: Track times across 2x2, 3x3, 4x4, and beyond
Improving Solve Times
Track your average over weeks to measure improvement. Record best singles and best averages separately—both matter in competition. Many cubers find their times improve dramatically with consistent timed practice versus casual solving.
Stopwatch for Public Speaking and Presentations
Speaker stopwatches help presenters practice timing and deliver talks within allocated slots. Our presentation stopwatch ensures you hit your time targets.
Presentation Practice
- Full run-throughs: Time complete presentations
- Section timing: Use laps to mark each major section
- Q&A allocation: Track how much time remains for questions
- Pacing practice: Hit time targets for each slide or topic
- Speech contests: Stay within competition time limits
Hitting Time Targets
Practice your presentation 3-5 times with the stopwatch to understand your natural pacing. Mark lap times at key transitions to know if you're running long or short. For countdown-based speaking, use our presentation timer which shows time remaining.
Stopwatch for Gaming and Speedruns
Speedrun timers track attempts to complete games as quickly as possible. Our gaming stopwatch helps speedrunners chase world records and personal bests.
Speedrunning Applications
- Full game runs: Track total completion time
- Split tracking: Mark each level or checkpoint
- Individual level (IL): Time single segments for optimization
- Practice sessions: Drill difficult sections repeatedly
- Race timing: Compete against other runners in real-time
Chasing Personal Bests
Speedrunning is about incremental improvement. Track your splits against your personal best to know if you're on pace for a new record. Even small time saves in each segment add up to significant overall improvements. Record your best times and analyze which segments have the most room for optimization.