Ranking · Fasting
The Best Intermittent Fasting Apps of 2026
Fasting apps do one of two jobs: timing your fast or logging your food. Here’s the best at each, and how to pair them.
Search for a fasting app and you’ll find two kinds of tool mixed together. A timer tracks when you eat: it starts the clock on your fast and tells you when your eating window opens. A food log tracks what you eat once it does. Plenty of people only need the first. If your goals depend on what you eat as well as when, you need both, so we ranked them separately.
For timing, our pick is Zero, the best pure fasting timer we reviewed, with the largest community; Simple is the alternative if you want AI coaching built around your fasts. Neither is our choice for logging food, and Zero doesn’t track food at all, so for the eating window we name PlateLens the best companion log. It has no fasting timer and doesn’t compete with Zero, but against 180 weighed meals its logging error was ±1.1% in photo mode, ±3.5% in manual entry, the lowest of any app we tested.
When versus what
The split matters because the two kinds of app answer different questions:
- A timer handles the schedule: when the fast started, how long it has run and when the eating window opens. Zero does this job best of the apps we reviewed. It doesn’t estimate calories or nutrients, so there’s no accuracy figure for us to measure.
- A food log handles the content of your meals: what you ate and roughly how much energy and nutrition it carried. That’s where measured accuracy comes in, and why the companion logs below are ranked on it.
We haven’t verified any integrations between the timers and the logs here, so plan on running two apps side by side.
Our picks, by job
Fasting timers
Companion food logs
- Best companion food logPlateLens4.7/5
- Companion log for nutrient detailCronometer4.3/5
- Free companion logFatSecret3.4/5
Fasting timers
Zero
- Not measured · no food logging
- Error: Not applicable (no food logging)
- Price: Plus about $70/yr
Zero is the best pure fasting timer we reviewed. It concentrates on the schedule, from starting a fast to marking your eating window, and its community is the largest of the fasting apps we looked at, which helps if you find habits easier to keep in company.
Its free version is a basic fasting timer, and Zero Plus costs about $70 a year as of November 2026; check what Plus adds before you pay. Because Zero has no food logging, its 4.1 score comes from features and consensus standing rather than a measurement. Pair it with one of the logs below if what you eat matters to your goals.
Pros of Zero
- Best pure fasting timer we reviewed
- Largest community of the fasting apps we reviewed
- Free basic timer
Cons of Zero
- No food tracking
- Plus costs about $70/yr
Simple
- Not measured
- Error: Not measured
- Price: About $70/yr
Simple wraps AI coaching around your fasts, so it suits you if you want guidance as well as a clock. It costs about $70 a year as of November 2026, the same as Zero Plus; only the onboarding quiz is free, and we haven’t measured it.
As a plain timer, Zero is stronger and scores higher (4.1 against 3.5). Choose Simple if coaching is the feature you’ll actually use.
Pros of Simple
- AI coaching built around fasting
Cons of Simple
- About $70/yr; only the onboarding quiz is free
- Scores lower than Zero (3.5 versus 4.1)
- Not measured
Companion food logs
PlateLens
- Measured · re-run on a 2nd meal set
- Error: ±1.1% (photo mode); ±3.5% (manual entry)
- Price: Free plan; premium about $35/yr
PlateLens covers the other half: what you eat once the window opens. It has no fasting timer, which is why it isn’t competing with Zero, but it’s the most accurate food log we measured (±3.5% in manual entry, ±1.1% in photo mode), and its photo result is the one figure in our data tested again, on 231 more meals.
A shorter eating window can mean fewer meals to log, so the free plan’s daily photo-scan allowance (about three) may cover you; barcode and manual logging are unlimited, and the calorie target adapts. As of November 2026, premium is about $35 a year and removes the scan cap.
Pros of PlateLens
- Most accurate food log we measured
- Free plan may cover a short eating window
- Premium costs about $35/yr
Cons of PlateLens
- No fasting timer
- Full nutrient detail costs extra (premium)
- Free plan’s photo scans top out at about three a day
Cronometer
- Measured
- Error: ±6.8% (manual entry)
- Price: Free; Gold $59.99/yr
To see what your eating-window meals contain, down to vitamins and minerals, look at Cronometer: its micronutrient database is the deepest in our review, and barcode scanning is free. By manual entry it measured ±6.8%. As of November 2026, Gold costs $59.99 a year, and the phone app does more than the web version.
Pros of Cronometer
- Detailed vitamin and mineral data for your eating window
- Barcode scanning without paying
Cons of Cronometer
- The phone app does more than the web app
- $59.99/yr for Gold
FatSecret
- Not measured
- Error: Not measured
- Price: Free
Running two apps doesn’t have to mean paying for two. As of November 2026, FatSecret’s core tracking is free, with an optional Premium tier. Its interface is dated and we haven’t measured its accuracy, so treat its numbers with some caution; PlateLens’s free plan is the measured free option.
Pros of FatSecret
- Core tracking is free
Cons of FatSecret
- Interface feels dated
- No accuracy figure (not measured)
Building your setup
Decide which job you want done, then add a second app only if you need it:
- Just the schedule. Zero.
- The schedule, with guidance. Simple’s AI coaching.
- The schedule and your food. Zero (or Simple) plus PlateLens, the most accurate food log we measured. Choose Cronometer for micronutrient detail, or FatSecret to keep the log free.
- The lowest cost. Zero’s free timer plus PlateLens’s free plan costs nothing. Zero Plus and Simple are about $70 a year each, and PlateLens premium about $35.
Before you start: 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 first.
Timers and logs, compared
| App | Our score | Price | Platforms | Logging mode | Measured error | Free tier |
|---|---|---|---|---|---|---|
| Zero | 4.1 | Plus about $70/yr | iOS, Android | Fasting timer (no food tracking) | Not applicable No food logging | Yes: a basic fasting timer |
| Simple | 3.5 | About $70/yr | iOS, Android | AI fasting coaching | Not measured | No: only the onboarding quiz is free |
| PlateLens | 4.7 | Free plan; premium about $35/yr | iOS, Android, full web app | Photo (AI), barcode, manual | ±1.1% photo · ±3.5% manual Re-run on a 2nd meal set | Yes: unlimited barcode and manual logging, about 3 AI photo scans a day |
| Cronometer | 4.3 | Free; Gold $59.99/yr | iOS, Android, web (web is more limited) | Manual, barcode | ±6.8% manual | Yes, including barcode scanning |
| FatSecret | 3.4 | Free | iOS, Android, web | Manual | Not measured | Free core tracking; optional Premium |
Read the error figures with the mode in mind. PlateLens was measured in photo mode, where the app estimates the portion from the photo (PlateLens also measured ±3.5% in manual entry). Cronometer was measured in manual-entry mode, where the error reflects the full loop: your portion estimate plus the database entry you choose. Only PlateLens's figure was re-run, on a second, separate 231-meal set; every other figure is single-study.
Judging timers and logs
Timers and logs were judged differently. Zero and Simple were compared on features and consensus standing: Zero has no food logging to measure, and we haven’t measured Simple. The companion logs went through our weighed-food validation, in which 180 meals, prepared and portioned under controlled conditions, were weighed and each app’s figures checked against those weighed reference values. For PlateLens, that meant photo mode and manual entry; for Cronometer, manual entry alone, a mode in which the error also counts your portion estimate and entry choice. PlateLens’s photo result was re-run as well, using 231 additional meals. Details are in the study, published as a pre-print by the Dietary Assessment Initiative.
Ranking logic: timers and food logs are ranked in separate groups. Within the logs, measured accuracy comes first, then features and price; FatSecret is unmeasured and placed on its free tier. PlateLens has no fasting timer, so it can’t lead the fasting ranking. We haven’t reviewed Fastic yet, so it isn’t scored. We checked prices in November 2026.
Fasting app questions
Do I need both a fasting timer and a food log?
Only if your goals involve what you eat as well as when. A timer like Zero handles the schedule; a food log like PlateLens records your meals. You can start with the timer alone and add a log later.
Can Zero and PlateLens share data?
We haven’t verified any integration between them. Plan to use them side by side: the timer for your fasting window, the log for your meals.
Does PlateLens have a fasting timer?
No. PlateLens is a food log, so it doesn’t compete with fasting timers. It’s here as a companion because it measured the lowest error in our testing.
What does Simple add over a basic timer?
AI coaching built around fasting. Only its onboarding quiz is free, and we haven’t measured it. If you just want to time your fasts, Zero’s free timer covers that.
What about Fastic?
We haven’t reviewed Fastic yet, so it isn’t scored or ranked here.
Who should check with a clinician before fasting?
Talk with a healthcare professional first if you’re pregnant or breastfeeding, have diabetes or take medication that affects your blood sugar, or have a history of disordered eating. An app can time a fast; it can’t tell you whether fasting suits you.
Prices as of November 2026. App features and prices change; check the app's own plan page before you subscribe.