All three are on this site, and the right one depends on whether the number you care about is known before you start or only after you stop.
Type the hours, minutes and seconds with the steppers, or press a preset (1, 3, 5, 10, 15, 30, 45 or 60 minutes). Press Start. Naming the timer puts the name under the digits and in the browser tab, so a glance at your tab strip tells you what is running.
Up to 99 hours, 59 minutes and 59 seconds. For anything past an hour, use the H field rather than counting minutes by hand.
The digits stop at zero, the progress bar empties, and the chosen alert plays. If the tab is in the background, a desktop notification appears as well — allow notifications the first time the browser asks.
Yes. Pressing Start again while it runs pauses it, and pressing it once more resumes from where it stopped. Reset returns to the length you last set.