Comparison

Zero vs iFast

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Zero

This app helps you track intermittent fasting and nutrition to achieve body composition changes. It integrates fasting, protein intake, meals, hydration, and habits for a holistic approach to weight loss and metabolic health.

Highlights
  • Intermittent fasting timers and streaks
  • Photo-based meal logging with macro analysis
  • Personalized daily protein targets
  • Water intake tracking
  • Habit tracking (movement, sleep, mood)
  • Progress visualization and trend analysis
  • Expert insights on fasting and nutrition
Features
Read full description

Zero is the all-in-one fasting tracker and nutrition app built for real results. Most fasting and weight loss apps stop at simply tracking fasts or calories. Zero connects the full picture — fasting, protein, meals, hydration, and habits — so you actually change your body composition, not just your eating schedule. Here’s how Zero helps you get there: • Track your intermittent fasting — Engage timers, streaks, and insights keep you stay motivated and consistent across your entire fasting journey. • Log meals the smart way — Skip the tedious manual meal entry routine. With Zero Plus, snap a photo and get instant macros, protein composition, and clarity on how effectively your meals support your goals. Your first meal logs are on us, so you can try it before you subscribe. • Hit your Protein Score — Zero Plus tracks a personalized daily protein target that adapts to your weight and goals. Better protein = better satiety, better muscle retention, better weight loss. Zero makes it automatic. • Complete the equation: Fasting + Protein — Most people fast or track meals. Zero brings them together so you lose weight, protect muscle, and avoid the pressure and guilt of traditional calorie trackers. • Stay hydrated to power your fasts — Water tracking with Zero Plus helps you maintain energy, reduce cravings, and support metabolic function throughout the day. • Build healthy habits that actually matter — Track movement, sleep, mood, and other daily pillars that reinforce your fasting and fueling routine. • Challenge yourself — Hit protein targets, maintain fasting streaks, and stay accountable with motivating challenges built around outcomes, not vanity metrics. • Learn the real science — Understand how fasting, protein, and hydration work together for sustainable weight loss and metabolic health — with insights from leading experts. • See measurable progress — Watch your streaks grow, your protein consistency rise, and your body composition improve with clean, insightful trend views. Whether you’re starting out or optimizing an existing routine, Zero gives you the structure, guidance, and clarity most apps miss. Zero is not a medical device and does not provide medical advice, diagnosis, or treatment. Always consult your doctor or qualified healthcare provider before making any changes to your diet, fasting routine, or health regimen. Zero is free to download, with fasting timers, streaks, weekly trends, expert articles, and challenges included. Zero Plus is an optional subscription that unlocks photo meal logging and your Protein Score, water tracking, custom fasts and saved presets, Fat-Burning Mode, the mood journal and daily habit insights, premium articles and Plus-only challenges, and monthly, yearly, and correlated charts. A free trial is available. Payment for Zero Plus will be charged to your Apple Account when you subscribe. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. Manage your subscription in your Account Settings. Read more terms & conditions: Terms of use: https://www.zerolongevity.com/terms-of-use Privacy policy: https://www.zerolongevity.com/privacy-policy

About

iFast

This app helps you track your fasting periods and monitor your progress towards your health goals. It supports various popular fasting methods, including circadian rhythm fasting and intermittent fasting schedules.

Highlights
  • Track fasting periods
  • Monitor progress
  • Support for popular fasting types
  • Circadian rhythm fasting
  • Intermittent fasting schedules
  • Custom prolonged fasts
Features
Read full description

iFast is your all-in-one intermittent fasting and healthy-living companion, and it is about far more than a timer. FASTING, DONE RIGHT • Any protocol: 14:10, 16:8, 18:6, OMAD or a custom window • A live timer with metabolic zones so you can see what your body is doing • Streaks, history and gentle reminders that keep you consistent HOME SCREEN AND LOCK SCREEN WIDGETS • The medium widget puts your fast, water, steps and food at a glance • A live countdown to your goal, so you always know how long is left • A small size for your fast and streak, plus Lock Screen widgets on iOS 16 and later • Tap a row in the medium widget to jump straight to logging it A COACH IN YOUR POCKET • Ask Ember, your personal coach, about fasting, food or training • Grounded, personalized guidance based on your goals and your logs ACCOUNTABILITY CIRCLES • Get matched into a small group on the same journey • Encourage each other and stay on track together TRACK WHAT MATTERS • Weight, water, steps, workouts and body measurements • Snap a photo of your meal for instant calorie and macro estimates • Clean charts that turn your data into visible progress APPLE HEALTH • Two-way sync so all your health data stays in one place iFast Pro unlocks photo meal analysis, higher coach limits and more. iFast Pro is an auto-renewable subscription. Payment is charged to your Apple ID at confirmation of purchase. It renews automatically unless canceled at least 24 hours before the end of the period; manage or cancel in your App Store account settings. Terms of Use: https://manuongithub.github.io/FastTrackerPolicies/termsofuse.html Privacy Policy: https://manuongithub.github.io/FastTrackerPolicies/privacypolicy.html

Screenshots

Zero4 screens
iFast4 screens

Verdict

The call

Zero and iFast both sit at 4.8 stars, but that hides the real split: 86% of iFast's written reviews are positive against 32% of Zero's. iFast also leads on in-app purchases (none vs 10) and update cadence (every 3 days vs every 2 weeks). Zero's advantage is ads (none vs shown) and ratings volume (445K vs 23). On price, rating and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Zero sells 8 in-app purchases, starting at $9.99 per month. iFast asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Zero holds the better App Store score, 4.8 against 4.7. That said, the two scores are not equally well evidenced: Zero has 445K ratings behind it against 23, so its average is the more settled of the two. Written reviews complicate that: 32% of Zero's written reviews are positive against 86% of iFast's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Zero ships an update every 2 weeks, iFast every 3 days. The most recent releases landed on November 10, 2026 and November 3, 2026 respectively.

Scorecard8 real differences · 3 level
Zero versus iFast: the parameters behind the verdict, then further details
ParameterZeroiFast
PriceFreeFree
Rating4.8 (445K ratings) — better4.7 (23 ratings)
Positive reviews32.0% of reviews85.7% of reviews — better
Number of ratings445K — better23
Update frequencyEvery 2 weeksEvery 3 days — better
AdsNo — betterYes
In-app purchasesYesNo — better
MonetizationFreemiumAd-supported — better
Best chart rank#119 — better—
DevicesiPhone, Apple WatchiPhone, iPad, iPod — better
Requires iOS17.015.1 — better
Further details — not scored
Size188 MB62 MB
Age rating17+4+
DeveloperZero Longevity Science, Inc.Manu Mehrotra

Customer experience

Zero

All ratings445,321 ratings
Positive96.3%
Neutral2.1%
Negative1.6%
Written reviews1,400 reviews
Positive32.0%
Neutral8.6%
Negative59.4%

iFast

All ratings22 ratings
Positive90.9%
Neutral0.0%
Negative9.1%
Written reviews14 reviews
Positive85.7%
Neutral0.0%
Negative14.3%

Bugs and requests

Zero

Reported bugs

3 issues
  • Password reset problems
  • Inaccurate fasting time tracking
  • Inability to exit trial without subscribing

Requested features

6 requests
  • Custom fasting periods longer than 24 hours
  • Ability to edit fasting type and duration
  • Integration with more health/fitness apps
  • Water intake tracking
  • Personalized fasting recommendations
Show 1 more
  • Improved data visualization and analytics

iFast

Not enough reviews yet to summarise bugs or requests.

In-app purchases

8 purchases

Zero

Subscriptions8
  • Zero Plus Subscription7 Days trial$9.991 Month
  • Zero Plus Subscription$9.991 Month
  • Zero Plus Subscription7 Days trial2 variants$69.991 Year
Show 5 more
  • Zero Plus Subscription$69.991 Year
  • Zero Plus Subscription1 Year trial2 variants$69.991 Year
  • Zero Plus Subscription1 Month trial$69.991 Year
  • Zero Plus Subscription1 Month trial$89.991 Year
  • Zero Plus Subscription7 Days trial$89.991 Year
None

iFast

No in-app purchases

Questions

Is Zero free?
Zero is free to download, with in-app purchases available.
Is iFast free?
iFast is free to download, with no in-app purchases.
Which has better reviews, Zero or iFast?
Zero is rated higher. Zero averages 4.8 out of 5 from 445K ratings, while iFast averages 4.7 from 23 ratings.
Do Zero or iFast have ads?
iFast shows ads; Zero does not.
Which is updated more often, Zero or iFast?
Zero ships an update every 2 weeks, and iFast every 3 days. Most recently, Zero was updated on November 10, 2026 and iFast on November 3, 2026.

Other comparisons