A free water tracker that takes one tap
Water is a free online water tracker. Set a daily goal, tap Glass or Bottle every time you drink, and the glass on screen fills toward your goal. Hit it and your streak grows by a day. Turn on reminders and we nudge you through the day.
No account, no app to install and no ads in the tracker. It saves to your browser, works offline, and installs on your home screen like an app.
How to use it
- Pick a daily goal: 1.5 to 3 liters, or 50 to 100 ounces, or type your own.
- Set your glass and bottle sizes once, so a tap logs the right amount.
- Tap each time you drink. Tapped by mistake? Undo it, or remove any drink from today's list.
- Turn on a reminder every 1, 2 or 3 hours and allow notifications.
How much water should I drink?
For most healthy adults, general guidance is about 2 to 3 liters of drinks a day (roughly 8 to 12 cups), more in hot weather, when you exercise, and when pregnant or breastfeeding. There is no exact number that fits everyone, and thirst is a reasonable guide for most people.
| Source | Women | Men | What it counts |
|---|---|---|---|
| US National Academies (2004) | 2.7 L total, about 2.2 L from drinks | 3.7 L total, about 3.0 L from drinks | All water, from drinks and food |
| EFSA, Europe (2010) | 2.0 L total | 2.5 L total | All water, from drinks and food |
| NHS, UK | 6 to 8 cups or glasses of fluid a day | Water, milk, sugar-free drinks, tea and coffee | |
These are amounts for a whole population, not a target you must hit to the milliliter. The "8 glasses of 8 ounces" rule is easy to remember, but a 2002 review by Heinz Valtin in the American Journal of Physiology found no scientific study behind it. A practical starting goal: 2 liters (about 68 ounces), then adjust to how you feel and how pale your urine is.
Not medical advice. If you have heart failure, kidney disease, or take medicines that affect fluid (like some diuretics), your doctor may want you to drink less, not more; follow their number. Drinking very large amounts in a short time can be dangerous.
Drink water reminders that do not nag
Free reminders come every 1, 2 or 3 hours between 9 AM and 9 PM. With Plus you can pick any interval, your own hours, a list of set times (like 8:00, 10:30, 13:00), and skip a reminder when you are already on track. Reminders fire while this page or the installed app is open, even in the background; a closed web page cannot wake itself up, so we tell you that up front rather than miss one silently.
Free, and what Plus adds
| Feature | Free | Plus |
|---|---|---|
| Daily goal, fill animation, ml or oz | Yes | Yes |
| Glass and bottle in your sizes, any amount | Yes | Yes |
| Streak and the last 7 days | Yes | Yes |
| Custom drinks (your mug, your gym bottle) | No | Yes |
| Reminders | Every 1, 2 or 3 hours, 9 AM to 9 PM | Any interval, your hours, set times, skip when on track |
| History and insights | No | 30-day chart, average, goal rate, best hour, CSV |
| Themes | Blue | + Mint, Lime, Ember, Bloom, Violet |
| Sync across devices | No (saved in this browser) | Yes |
Tensorust Plus is $2.99 a month or $14.99 a year, and the yearly plan starts with a 7-day free trial. One subscription covers Water and Focus, Habits, Sleep and Fasting. It renews until you cancel, and you can cancel anytime from the Plus page.
Questions
How much water should I drink a day?
There is no single number. The US National Academies set an adequate intake of about 3.7 liters of total water a day for men and 2.7 liters for women, from all drinks and food; about 80% usually comes from drinks, so roughly 3 liters and 2.2 liters. Europe's food safety agency (EFSA) says 2.5 and 2.0 liters of total water. You need more in heat, when you exercise, and when pregnant or breastfeeding. This is general guidance, not medical advice.
Do I really need 8 glasses a day?
Not exactly. The "8 glasses of 8 ounces" rule is a handy round number, but a 2002 review in the American Journal of Physiology found no scientific study behind it. The UK NHS suggests 6 to 8 cups or glasses of fluid a day as a rough guide, and tea, coffee and milk count.
Is this water tracker free?
Yes. The daily goal, one-tap glass and bottle in your sizes, any other amount, the streak, the last 7 days and reminders every 1, 2 or 3 hours are free with no sign-up. Tensorust Plus ($2.99 a month or $14.99 a year) adds history and insights, custom drinks, themes, more reminder schedules and sync.
How do the drink water reminders work?
Turn them on and allow notifications. You get a gentle nudge on your schedule between 9 AM and 9 PM. They fire while this page or the installed app is open, even in the background; browsers do not let a closed web page wake itself up, so if you close it the reminders pause until you open it again.
Does coffee or tea count?
Yes. The NHS counts tea and coffee toward your fluids, and the US National Academies count all drinks. Log them as they are. With Plus you can add a "Coffee" or "Tea" button in your mug size.
Can I use ounces?
Yes. Switch between milliliters and US fluid ounces at any time; everything you logged converts.
Can I drink too much water?
Yes, it is possible, though rare. Drinking very large amounts in a short time, for example during long endurance events, can dilute the sodium in your blood (hyponatremia). People with heart failure, kidney disease or on some medicines may be told to limit fluids. Follow your doctor's advice over any app goal.
Where is my data stored?
In your browser, on your device. We cannot see it. With Plus sync, a copy is stored with your Tensorust account so your other devices get it, and you can delete it any time from the Plus page.
Sources
- Institute of Medicine (National Academies). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academies Press, 2004 (published 2005).
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for water. EFSA Journal 2010;8(3):1459.
- NHS. Water, drinks and your health (Eat well).
- Valtin H. "Drink at least eight glasses of water a day." Really? Is there scientific evidence for "8 x 8"? American Journal of Physiology 2002;283(5):R993-R1004.
Want it as a habit?
There is no Water iPhone app from us. If you would rather track water next to your other habits, Habits has a "Drink water, 8 glasses" habit in one tap, and Focus keeps you company while you work.
Keep going
- FocusA focus timer with eyes that watch you work. Free.
- HabitsOne-tap habit tracker with streaks and a year quilt. Free.
- SleepSleep sounds you can mix, a fade-out timer and a sleep log. Free.
- FastingIntermittent fasting timer: 16:8, 18:6, 20:4, OMAD. Free.
- Tensorust PlusHistory and insights, custom drinks, themes, sync.
- Free toolsCalculators and converters, no sign-up.