Online swimming pace clock and send-off timer
Run a high-visibility four-hand pool clock for interval starts, fixed send-offs, and synchronized sessions—free in any modern browser.
New to pool clocks? Learn how to read the hands and calculate send-offs.
Pool timing
Pace clock controls
Use real wall-clock seconds or start a synchronized session clock for send-offs.
Hand start positions
- 00 seconds
- 15 seconds
- 30 seconds
- 45 seconds
Built for the pool deck
One clock. Four start colors. Every swimmer synchronized.
Use Visible mode on a phone, tablet, laptop, or deck-side display, and keep the screen where swimmers can read it from the wall. Session mode starts every hand from a shared zero; Wall Clock mode stays aligned with the current minute.
Each swimmer follows one colored hand, so a crowded lane can stagger starts off a single clock.
How to read the hands and stagger a laneQuick reference
Common send-offs, ready to set.
Pick the row that matches the repeat you are about to swim, then set that interval above.
| Expected swim | Planned rest | Send-off |
|---|---|---|
| 1:20 | :10 | 1:30 |
| 1:30 | :15 | 1:45 |
| 1:35 | :15 | 1:50 |
| 1:40 | :20 | 2:00 |
For custom distances and exact repeat targets, use the swim pace and send-off calculator.
Choose the timing model
Wall clock for familiarity. Session clock for a shared zero.
- Wall Clock
- Matches the current minute, so swimmers can join an established pool schedule and read it like a traditional deck clock.
- Session
- Begins from zero when started, keeping a coach, squad, or remote screen synchronized to the same elapsed time.
Online swimming pace-clock questions
What is a swimming pace clock?
A swimming pace clock is a continuously running 60-second clock used to coordinate interval starts, rest, and send-offs. Traditional pool clocks use multiple colored hands separated by 15 seconds.
How do I use the Swimio online pace clock?
Use Wall Clock mode to stay aligned with the current minute, or Session mode to begin from a shared zero. Select a send-off interval, optionally enable a tone, and open Visible mode for the largest possible display.
Does the pace clock work on phones and tablets?
Yes. The clock is responsive and supports browser full-screen mode where the device allows it. Keep the device protected from water and use your display settings to prevent sleep during long sessions.
Is the Swimio swimming pace clock free?
Yes. It runs in the browser without an account. Swimio on Apple Watch adds wrist-based pace-clock timing and structured workout guidance in the water.