Comparison

Fasty vs Fast Slow

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

Head to head
About

Fasty

This app offers a straightforward and privacy-focused way to track intermittent fasting. It provides tools for timing fasts, monitoring weight and BMI, and maintaining progress streaks without requiring sign-up or displaying ads.

Highlights
  • One-tap fasting timer
  • Multiple fasting programs
  • Custom fast durations
  • Weight tracking
  • BMI tracking
  • Progress and streak tracking
  • Ad-free experience
Features
Read full description

Fasty – The Simplest Way to Track Your Fast No ads. No sign up. Just fasting. Fasty is the most minimal, privacy-friendly intermittent fasting tracker on the App Store. Whether you’re just getting started or deep into your fasting journey, Fasty helps you stay consistent—without distractions or data collection. No accounts. No emails. No tracking—except your fasts (and your weight, if you want). What You’ll Get: - One-tap fasting timer - Tons of different fasting programs - Custom Fast Durations - Simple weight tracking - Easy BMI Tracking - Streaks & progress tracking - Clean, distraction-free design - Absolutely no ads Whether you’re doing a 16:8 fast, OMAD, or something custom, Fasty makes it easy to stay on track with your health goals—without giving up your privacy. Fasting doesn’t have to be complicated. Download Fasty and keep it simple. Our app uses the accepted BMI formula of BMI = kg/m2 more info can be found here: https://www.heartfoundation.org.au/bmi-calculator Terms Of Use can be found at: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy policy: https://www.termsfeed.com/live/05dde8a0-027e-412a-91ba-690f48580523

About

Fast Slow

Understand your body's metabolic changes during fasting with a visual timeline. This free app guides you through different fasting zones, from digestion to deep ketosis, and offers customizable schedules and smart notifications. It provides stats, streaks, and widgets for easy progress tracking.

Highlights
  • Fasting timer with visual timeline
  • 6 customizable fasting schedules
  • 5 distinct fasting zones explained
  • Smart notifications for fasting windows
  • Stats, streaks, and trends tracking
  • Home and Lock Screen widgets
  • Siri Shortcuts integration
Features
Read full description

See what happens inside your body as you fast. Fast Slow walks you through 5 fasting zones, from digestion through fat burning to deep ketosis, so you understand what every hour of your fast is doing. 100% free. Every feature. No ads. No paywalls. No trackers. Free forever. WHAT MAKES FAST SLOW DIFFERENT Most fasting apps just count down a timer. Fast Slow shows you what's actually happening in your body at each stage: - Anabolic (0-4h): Digesting and storing nutrients - Catabolic (4-8h): Tapping into energy reserves - Fat Burning (8-12h): The metabolic switch - Ketosis (12-16h): Ketones and cellular cleanup - Deep Ketosis (16h+): Deep cellular renewal Tap any zone to learn more about the science behind it. 100% FREE. EVERY FEATURE INCLUDED. No premium tier. No trial that expires. No paywall gates. Every feature in Fast Slow is yours from day one: - All 6 fasting schedules - All stats, streaks, and trends - All widgets (Home Screen and Lock Screen) - All notifications - Siri Shortcuts - iCloud sync - Data export Everything free. No catches. FEATURES Fasting Timer One tap to start. One tap to stop. A visual timeline shows where you are, what zone you're in, and what comes next. 6 Fasting Schedules 12:12 for beginners, 14:10, 16:8 (the most popular), 18:6, 20:4, and OMAD (one meal a day) for experienced fasters. Visual Timeline Color-coded timeline of your fasting and eating windows. Plan meals, training, and recovery at a glance. Smart Notifications 7 notification types: goal reached, halfway there, one hour left, eating window alerts, and a custom last meal reminder. Nudges, not nags. Stats & Streaks Total fasts, average duration, personal records, weekly trends, and a monthly fasting calendar. Small wins add up. Widgets Home Screen and Lock Screen widgets with progress rings, timelines, and live timers. Check your fast without opening the app. Siri Shortcuts "Hey Siri, start my fast." Start, stop, and check your fasting status hands-free. AI-Powered Greetings On supported devices, Apple Intelligence creates personalized messages based on your fasting progress, streak, and time of day. iCloud Sync Your fasting data syncs automatically across all your devices. Data You Own Export your fasting history as JSON. Delete everything with one tap. Your data, your choice. DESIGNED FOR REAL LIFE Pick a schedule, adjust as needed, and let Fast Slow handle the timing. New to fasting or already have a routine, it works either way. Structure when you want it, out of the way when you don't. Built by one developer who fasts every day. No corporate agenda. No growth hacking. A well-made tool that respects your time and your data. RESPONSIBLE APPROACH Intermittent fasting can support weight management, energy, and focus, but results vary. Fast Slow provides tools and information, not medical advice. If you have health conditions, are pregnant, or have a history of eating disorders, please talk to a healthcare professional before starting. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://cernezan.com/fast-slow/privacy/

Screenshots

Fasty3 screens
Fast Slow4 screens

Verdict

The call

The clearest difference is review sentiment: Fast Slow at 100% against Fasty's 8%. Fast Slow also leads on update cadence (every 2 weeks vs every 9 months) and monetization model (free vs free with in-app purchases). Fasty's advantage is ratings volume (1.5K vs 39) and iOS requirement (16.5 vs 18.0). On price, ads, 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. Fasty sells 3 in-app purchases, starting at $9.99 per 7 days and Fast Slow sells 4 in-app purchases, starting at $1.99 per 7 days. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Fast Slow holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Fasty has 1.5K ratings behind it against 39, so its average is the more settled of the two. Written reviews point the same way: 8% of Fasty's written reviews are positive against 100% of Fast Slow's.

UpkeepUpdate frequency

Fasty ships an update every 9 months, Fast Slow every 2 weeks. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

Scorecard6 real differences · 4 level
Fasty versus Fast Slow: the parameters behind the verdict, then further details
ParameterFastyFast Slow
PriceFreeFree
Rating4.7 (1.5K ratings)5.0 (39 ratings) — better
Positive reviews7.7% of reviews100.0% of reviews — better
Number of ratings1.5K — better39
Update frequencyEvery 9 monthsEvery 2 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad — betteriPhone
Requires iOS16.5 — better18.0
Further details — not scored
Size5 MB23 MB
Age rating4+4+
DeveloperGabe RogersZan Cerne

Customer experience

Fasty

All ratings1,526 ratings
Positive91.2%
Neutral5.4%
Negative3.3%
Written reviews13 reviews
Positive7.7%
Neutral7.7%
Negative84.6%

Fast Slow

All ratings36 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

3 purchases

Fasty

Subscriptions3
  • Weekly$9.997 Days
  • Monthly$24.991 Month
  • Annual7 Days trial$34.991 Year
4 purchases

Fast Slow

Subscriptions2
  • Legacy$1.997 Days
  • Legacy - Yearly3 Days trial$12.991 Year
One-time2
  • Buy Me a Coffee$2.99
  • You're Amazing$9.99

Questions

Is Fasty free?
Fasty is free to download, with in-app purchases available.
Is Fast Slow free?
Fast Slow is free to download, with in-app purchases available.
Which has better reviews, Fasty or Fast Slow?
Fast Slow is rated higher. Fasty averages 4.7 out of 5 from 1.5K ratings, while Fast Slow averages 5.0 from 39 ratings.
Do Fasty or Fast Slow have ads?
Neither Fasty nor Fast Slow shows ads.
Which is updated more often, Fasty or Fast Slow?
Fasty ships an update every 9 months, and Fast Slow every 2 weeks. Most recently, Fasty was updated on October 25, 2026 and Fast Slow on October 24, 2026.

Other comparisons