Comparison

Zero vs Fast

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 tracks intermittent fasting and nutrition to help users achieve real 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
  • Smart meal logging with photo recognition
  • Personalized daily protein target tracking
  • Integrated fasting and protein tracking
  • Water and habit tracking
  • Science-based 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

Fast

This app helps you track intermittent fasting routines, monitor progress, and analyze health data. It offers educational content, motivational challenges, and a journal to record your feelings. Connect with friends for support and motivation on your wellness journey.

Highlights
  • Fasting timer and tracker
  • Progress analytics and history
  • Educational 'Know It' section
  • Motivational challenges and trophies
  • Mood tracker and journal
  • Health app integration (steps)
  • Fasting buddy feature
Features
Read full description

Fast: Fasting Tracker & Timer helps you build consistent fasting habits with flexible fasting plans, body weight logging, water intake tracking, reminders, and detailed progress insights. Whether you're new to intermittent fasting or already following a routine, the app provides the tools to stay organized and work toward your personal health and wellness goals. Choose a fasting plan, customize your schedule, and track every fast in one place with an easy-to-use fasting tracker. FASTING PLANS Find a fasting schedule that works for your lifestyle. Choose from 12:12, 13:11, 14:10, 15:9, 16:8, 17:7, 18:6, 19:5, 20:4, 21:3, 22:2, 23:1, MWF, TTS, or create your own custom fasting plan. Whether you're starting intermittent fasting or maintaining an existing routine, you can choose a plan that suits your goals. FASTING TRACKER & TIMER Track active and completed fasts with an intuitive fasting tracker and timer. Review your fasting history and monitor your consistency over time. BODY WEIGHT & WATER TRACKING Log your body weight and monitor changes throughout your fasting routine. Track your daily water intake to stay hydrated and build healthier habits alongside your fasting schedule. SMART REMINDERS Stay on schedule with fasting reminders and water intake reminders. Customize notifications to help you start and end your fasting window on time while maintaining your daily hydration routine. ANALYTICS & HISTORY Review your fasting sessions, body weight, hydration logs, activity, and history with easy-to-understand analytics that help you monitor your progress and stay consistent. INFORMATIVE BLOGS Learn more about intermittent fasting through informative blogs covering healthy habits, wellness topics, and practical guidance to help you better understand your fasting routine. FASTING BUDDIES Stay motivated by fasting together. Invite friends, track each other's progress, and encourage one another throughout your fasting journey with the Buddy feature. ACTIVITY SUPPORT Sync your activity data to keep your fasting progress and daily activity organized in one place for a more complete overview of your routine. Whether you're following a 16:8 fasting schedule, exploring different intermittent fasting plans, or creating a custom fasting routine, Fast: Fasting Tracker & Timer gives you the tools to stay organized and build lasting healthy habits. DISCLAIMER This app is intended for informational and lifestyle purposes only and does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before starting any fasting routine, especially if you have an existing medical condition, are pregnant, or have specific dietary requirements. PRIVACY POLICY https://maximaapps.com/fasting/privacy_policy.html TERMS OF USE https://maximaapps.com/fasting/terms-of-use.html GET IN TOUCH Have questions, feedback, or suggestions? We'd love to hear from you. Contact us through the app or email us at feedback@maximaapps.com.

Screenshots

Zero4 screens
Fast4 screens

Verdict

The call

Zero and Fast both sit at 4.8 stars, but that hides the real split: 75% of Fast's written reviews are positive against 33% of Zero's. Zero's advantage is ratings volume (445K vs 3.3K) and update cadence (every 2 weeks vs every 2 months). On price, rating, ads and in-app purchases 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 10 in-app purchases, starting at $9.99 per month and Fast sells 8 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Zero against 4.7 for Fast. That said, the two scores are not equally well evidenced: Zero has 445K ratings behind it against 3.3K, so its average is the more settled of the two. Written reviews are what separate them: 33% of Zero's written reviews are positive against 75% of Fast's.

UpkeepUpdate frequency

Zero ships an update every 2 weeks, Fast every 2 months. The most recent releases landed on September 24, 2026 and September 23, 2026 respectively.

Scorecard4 real differences · 7 level
Zero versus Fast: the parameters behind the verdict, then further details
ParameterZeroFast
PriceFreeFree
Rating4.8 (445K ratings) — better4.7 (3.3K ratings)
Positive reviews32.6% of reviews74.6% of reviews — better
Number of ratings445K — better3.3K
Update frequencyEvery 2 weeks — betterEvery 2 months
AdsNoNo
In-app purchasesYesYes
MonetizationFreemiumFree with in-app purchases
Best chart rank#115 — better—
DevicesiPhone, Apple WatchiPhone, iPad, Apple Watch — better
Requires iOS17.0 — better18.6
Further details — not scored
Size238 MB116 MB
Age rating17+12+
DeveloperZero Longevity Science, Inc.Maxima Apps

Customer experience

Zero

All ratings445,297 ratings
Positive96.3%
Neutral2.1%
Negative1.6%
Written reviews1,364 reviews
Positive32.6%
Neutral8.6%
Negative58.9%

Fast

All ratings3,286 ratings
Positive91.8%
Neutral4.8%
Negative3.4%
Written reviews189 reviews
Positive74.6%
Neutral10.6%
Negative14.8%

User reviews

Zero

From 445K App Store ratings

What we love

  • 🚀 Easy to use
  • 📊 Helpful tracking and data
  • 💡 Informative learning resources
  • 🔍 Detailed fasting information
  • 🤝 Sense of community

Room to improve

  • 💰 Expensive premium subscription
  • 🔒 Forced account creation
  • 🙄 Intrusive ads and upsells
  • 🤔 Inconsistent or confusing UI changes
  • 🐛 Syncing and login issues

Fast

From 3.3K App Store ratings

What we love

  • 🚀 Easy to use
  • 👍 Helpful for weight loss
  • 👍 Motivating with trophies
  • 👍 Customizable fasting plans
  • 👍 Integrates with health apps

Room to improve

  • 🐛 Timer issues/inaccuracies
  • 🐛 Inability to edit fasting times
  • 🐛 Syncing/data saving problems
  • 🐛 Crashes and glitches
  • 🔍 Lacking advanced features

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

Fast

Reported bugs

3 issues
  • Timer not accurately recording fasting times
  • Inability to update weight in app
  • Crashing when trying to view friend's status

Requested features

4 requests
  • Option to edit fasting start/end times
  • More detailed analytics and progress tracking
  • Improved syncing and data saving reliability
  • Expanded customization options

In-app purchases

10 purchases

Zero

Subscriptions10
  • Zero Plus Subscription2 variants$9.991 Month
  • Zero Plus Subscription7 Days trial$9.991 Month
  • Zero Plus Subscription$39.991 Year
Show 7 more
  • Zero Plus Subscription7 Days trial$49.991 Year
  • Zero Plus Subscription7 Days trial3 variants$69.991 Year
  • Zero Plus Subscription$69.991 Year
  • Zero Plus Subscription1 Year trial3 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
8 purchases

Fast

Subscriptions6
  • Fast Premium Monthly$4.991 Month
  • Fasting Monthly$14.991 Month
  • Fasting Annually$19.991 Year
Show 3 more
  • Fasting Premium$27.993 Months
  • Fast Premium Yearly$29.991 Year
  • Fasting Premium Yearly$39.991 Year
One-time2
  • Fasting One Time Special Offer$19.99
  • Fasting Pro$49.99

Questions

Is Zero free?
Zero is free to download, with in-app purchases available.
Is Fast free?
Fast is free to download, with in-app purchases available.
Which has better reviews, Zero or Fast?
Zero is rated higher. Zero averages 4.8 out of 5 from 445K ratings, while Fast averages 4.7 from 3.3K ratings.
Do Zero or Fast have ads?
Neither Zero nor Fast shows ads.
Which is updated more often, Zero or Fast?
Zero ships an update every 2 weeks, and Fast every 2 months. Most recently, Zero was updated on September 24, 2026 and Fast on September 23, 2026.

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