Comparison

Zero vs Fasting Clock

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

Fasting Clock

Features
Read full description

Simple Fasting Clock is a clean, easy intermittent fasting timer that helps you stay consistent—without complicated setup. Start your fast, watch the progress ring, and see exactly how much time is left. During your fast, you’ll also get simple fasting phase insights (Fed → Fat Burning → Deep Ketosis) to stay motivated. FEATURES • One-tap fasting timer with auto-complete • Presets: 16:8, 18:6, 20:4 (Warrior), 23:1 (OMAD) • Custom fasting duration from 1 to 72 hours • Live progress ring with time left and percentage • Fasting phase guide with clear explanations • History log for every fast (completed or ended early) • Stats: completed fasts, total hours fasted, average duration, and day streak • Achievements to celebrate milestones • Daily quote + daily tip for motivation • Designed for iPhone and iPad • No account required DISCLAIMER This app is for informational purposes only and is not medical advice. If you have a medical condition, are pregnant, or are under 18, consult a healthcare professional before fasting. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Zero4 screens
Fasting Clock4 screens

Verdict

The call

The clearest difference is ads: Zero at none against Fasting Clock's shown. Zero also leads on update cadence (every 2 weeks vs every 5 months) and chart position (#133 vs unranked). Fasting Clock's advantage is iOS requirement (13.0 vs 17.0). On price, in-app purchases 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 and Fasting Clock sells 3 in-app purchases, starting at $0.99 per 7 days. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Zero ships an update every 2 weeks, Fasting Clock every 5 months. The most recent releases landed on November 11, 2026 and November 5, 2026 respectively.

Scorecard4 real differences · 7 level
Zero versus Fasting Clock: the parameters behind the verdict, then further details
ParameterZeroFasting Clock
PriceFreeFree
Rating4.8 (445K ratings) — better—
Positive reviews32.0% of reviews—
Number of ratings445K — better—
Update frequencyEvery 2 weeks — betterEvery 5 months
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFreemium—
Best chart rank#133 — better—
DevicesiPhone, Apple WatchiPhone, iPad, iPod — better
Requires iOS17.013.0 — better
Further details — not scored
Size188 MB23 MB
Age rating17+4+
DeveloperZero Longevity Science, Inc.Afriwan Ahda

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

Fasting Clock

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
3 purchases

Fasting Clock

Subscriptions3
  • Weekly Premium Access$0.997 Days
  • Monthly Premium Access$2.991 Month
  • Yearly Premium Access$17.991 Year

Questions

Is Zero free?
Zero is free to download, with in-app purchases available.
Is Fasting Clock free?
Fasting Clock is free to download, with in-app purchases available.
Do Zero or Fasting Clock have ads?
Fasting Clock shows ads; Zero does not.
Which is updated more often, Zero or Fasting Clock?
Zero ships an update every 2 weeks, and Fasting Clock every 5 months. Most recently, Zero was updated on November 11, 2026 and Fasting Clock on November 5, 2026.

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