Zero Review: The Best Pure Fasting Timer

Zero is an intermittent fasting app that does one job and does it well. It’s the best pure fasting timer we reviewed, and it has the largest community of the fasting apps we looked at. It doesn’t track food at all, which is either a strength or a gap, depending on what you want.

Here’s how to decide whether Zero is enough on its own.

What Zero does well

It’s a focused fasting timer. Zero is built around timing your fasts, and it’s the best pure fasting timer we reviewed. If you want an app that starts, tracks and ends your fasting windows without asking you to log meals, it does exactly that.

It has the largest community. Of the fasting apps we reviewed, Zero’s community is the largest. If you find it easier to stick with a habit when you know many others are doing the same, that counts for something.

Where it falls short

No food tracking. Zero tells you when you’re fasting, not what you eat when you aren’t. If your goals depend on what’s on your plate as well as when, you’ll need a second app.

Plus isn’t cheap. Zero Plus costs about $70 a year as of November 2026. That’s the same ballpark as Simple (about $70), and double what PlateLens charges for food-logging premium (about $35).

Accuracy: not applicable

Our accuracy testing measures how close an app’s food log comes to weighed reference values across 180 meals. Zero has no food logging, so there’s nothing for that test to measure. We label it “Not measured” for that reason, and its 4.1 score rests on features and consensus standing.

Free vs paid

As of November 2026, the free version gives you a basic fasting timer, and Zero Plus costs about $70 a year. Check the plan page in the app for what Plus adds before you subscribe.

Pairing Zero with a food log

If you fast, you may also want to know what you eat during your eating window. Because Zero doesn’t log food, the practical answer is two apps: Zero for timing, and a food log for intake.

Our pick for that second app is PlateLens. It’s the most accurate food log we measured (±1.1% in photo mode, ±3.5% in manual entry), and its free plan includes unlimited barcode and manual logging. PlateLens doesn’t have a fasting timer, which is exactly why the two fit together. Cronometer is a good alternative if you want deep micronutrient detail.

Who it’s for

• You want a dedicated fasting timer and nothing more.
• You like the idea of a large community around you.
• You already have a food log, or you don’t need one.

Who should skip it

• You want fasting and food tracking in one app. Zero doesn’t log food.
• You want AI coaching around your fasts. Simple is built around it.

Before you start fasting

Intermittent fasting isn’t right for everyone. If you’re pregnant or breastfeeding, have diabetes or take medication that affects your blood sugar, or have a history of disordered eating, talk with a healthcare professional before you start.

The bottom line

Zero is the best pure fasting timer we reviewed, with the largest community behind it. It doesn’t track food, so if you want to know what you eat as well as when, pair it with a food log such as PlateLens.