20-20-20 screen break timer
Work for 20 minutes, then look at something about 20 feet away for 20 seconds.
Breaks this session: 0
A 20-20-20 timer is a simple way to remember screen breaks without watching the clock. Start it when you begin focused screen work. After 20 minutes, the page opens a 20-second look-away prompt and then starts the next work interval.
What the 20-20-20 rule means
The rule is straightforward: for every 20 minutes spent on close screen work, look at something about 20 feet away for at least 20 seconds. The American Optometric Association includes this habit in its guidance for computer work.
The evidence deserves a careful description. Regular breaks are a reasonable, low-cost habit and the rule is widely recommended, but the exact 20-minute and 20-second formula does not have a large, decisive research base. A peer-reviewed review of digital eye strain guidance found that evidence for the specific rule is limited and that break research has produced mixed results. That makes this timer a useful reminder, not a proven treatment.
How to use this screen break timer
- Select Start timer when a work session begins.
- Keep this tab open. You can work in another tab or application while it counts down.
- When the break prompt appears, look across the room or out a window at something roughly 20 feet away.
- After 20 seconds, the next work interval begins automatically. Use End break now if you need to dismiss it early.
Sound is off by default. Browser notifications are also opt-in and the timer fails softly if your browser does not support them or you deny permission. The session counter is deliberately local to this open page. Resetting or reloading starts the count over, and no timer data is sent anywhere.
The timer is only one part of a comfortable setup
A break reminder cannot correct glare, tiny text, an awkward monitor position, or a viewing distance that makes you lean forward. Use the monitor viewing distance calculator to check how far you sit from the display. Then use the monitor height guide to set the screen without forcing your head up or down.
Brightness should feel appropriate for the room rather than maximized by default. Increase text size before moving closer, keep reflections out of the direct viewing path, and remember to blink. These are practical setup adjustments, not guarantees that symptoms will disappear. If discomfort is persistent, new, severe, or interfering with work, an eye-care professional can assess factors that a browser timer cannot.
Frequently asked questions
What is the 20-20-20 rule?
After 20 minutes of close screen work, look at something about 20 feet away for at least 20 seconds. It is a memory aid for taking brief visual breaks.
Does the 20-20-20 rule have strong scientific evidence?
No strong claim is warranted. Eye-care organizations recommend the habit, but research on this exact timing formula is modest and findings on scheduled breaks are mixed. It is best treated as a reasonable reminder rather than a medical intervention.
Does this timer keep running in a background tab?
Yes. It calculates remaining time from the browser clock rather than assuming every timer tick arrives exactly on schedule. Browser power-saving features can delay the visible update, so the optional notification can be useful when the tab is hidden.
Will this timer fix eye strain?
No. It is a break reminder, not medical advice, and it cannot diagnose, prevent, or treat an eye condition. Screen comfort can also involve blinking, glare, text size, viewing distance, monitor position, room lighting, and vision correction.