90 Minute Timer
One click, alarm when time is up
Set a 90 Minute Timer
Press Start and this page counts down exactly 90 minutes, then plays a clear alarm. The remaining time shows in the browser tab, so you can work in another window and still see it.
One full ultradian focus cycle — or one complete sleep cycle for the perfect long nap.
Runs entirely in your browser — free, instant, no signup.
Frequently Asked Questions
Do I need to keep this tab open?
Keep the browser running; the tab title shows the countdown even when you're on another tab.
Can I pause it?
Yes — Pause and Reset buttons are right under the display.
Is the 90 minute timer accurate?
It ticks on a 1-second interval from your device clock — accurate for everyday timing.
Is it free?
Yes, completely free.
Related Tools
Need a different length? Try the custom timer or the Pomodoro Timer.
设一个90 分钟计时器
点击开始，页面精确倒数 90 分钟，结束时播放清晰的提示音。剩余时间会显示在浏览器标签页标题上，切到别的窗口也看得见。
一个完整的超昼夜专注周期——或一个完整睡眠周期，适合完美长午睡。
完全在浏览器内运行——免费、即开即用、无需注册。
常见问题
需要一直停在这个页面吗？
浏览器开着即可；切到其他标签页时，标题栏仍显示倒计时。
可以暂停吗？
可以——显示屏下方就有暂停和重置按钮。
计时准吗？
基于设备时钟每秒跳动，日常计时完全够准。
免费吗？
是的，完全免费。