Comparison

9toFast vs FastZen

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

Head to head
About

9toFast

Features
Read full description

9toFast is a clean and intuitive intermittent fasting app designed to help you stay consistent without pressure. Whether you’re fasting for better focus, energy, or health, 9toFast makes it easy to track your progress and feel in control. Stay on track effortlessly β€’ Smart fasting timer: Start, pause, or end your fasts anytime and watch your fasting ring fill in real-time. β€’ Custom fasting plans: Choose from popular plans like 16:8 or 18:6, or set your own window. β€’ Progress dashboard: Visualise your streaks and completion rates at a glance. β€’ Personalised themes: Match your app to your mood with sleek light and dark options. β€’ Simple insights: See how your fasting habits evolve over time with easy-to-read stats. Why users love 9toFast β€’ Minimal design that keeps fasting simple β€’ No clutter, ads, or confusing features β€’ Built for balance, not restriction Perfect for beginners and pros Whether you’re new to fasting or have been doing it for years, 9toFast adapts to your lifestyle. Track your fasts, stay consistent, and celebrate small wins daily. Coming soon β€’ Weight tracking β€’ Calorie Counting β€’ Meal Logging β€’ Health app integrations β€’ Fasting challenges β€’ Custom reminders and streak rewards Start your fasting journey today with 9toFast: the fasting tracker that’s simple, motivating, and built for real life.

About

FastZen

This app helps you manage your fasting schedule with customizable timers and reminders. It offers a recurring weekly routine, a timer that remembers your progress, and a clear view of your active fast. Review your history and track your streaks, all while keeping your data private on your device.

Highlights
  • Customizable fasting schedules
  • Recurring weekly routine setup
  • Live Activities for active fast tracking
  • Detailed fasting history and streaks
  • No account, ads, or server sync
  • Custom Week one-time purchase
Read full description

FastZen tracks your fast and lets you move one date without rewriting your weekly routine. Dinner running late? Adjust that day and keep the rest of your week. Preview the next 7 days, including start times, planned finishes and rest days. β€’ Start a 16:8, 18:6, 20:4 or OMAD (23-hour) fast. β€’ Set a custom duration from 1 to 48 hours. β€’ See elapsed time, remaining time and your planned finish. β€’ Review completed sessions and correct their times. β€’ Repeat one start time on the weekdays you choose. Your active session stays saved when you close the app. No account, no ads and no server sync. The widget puts your fast on the Home Screen. On iPhone, a Live Activity shows your session on the Lock Screen for up to 8 hours, the iOS limit. The session stays saved in the app. FastZen is a tracking tool, not medical advice or a promise of weight loss. Custom Week is a one-time purchase with no subscription. It unlocks a separate plan and start time for each weekday, rest days, and changes to a single date without changing your recurring week. People who used FastZen before version 1.1.0 keep that access without paying.

Screenshots

9toFast4 screens
FastZen4 screens

Verdict

The call

The clearest difference is ads: FastZen at none against 9toFast's shown. 9toFast's advantage is iOS requirement (15.1 vs 17.0). On price, update cadence, in-app purchases and device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. 9toFast sells 3 in-app purchases, starting at $0.99 per month and FastZen sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

9toFast ships an update fortnightly, FastZen weekly. Both last shipped on October 28, 2026.

Scorecard2 real differences Β· 6 level
9toFast versus FastZen: the parameters behind the verdict, then further details
Parameter9toFastFastZen
PriceFreeFree
Positive reviewsβ€”100.0% of reviews
Update frequencyFortnightlyWeekly β€” better
AdsYesNo β€” better
In-app purchasesYesYes
Monetizationβ€”Free with in-app purchases
DevicesiPhone, iPad, iPod β€” betteriPhone, iPad
Requires iOS15.1 β€” better17.0
Further details β€” not scored
Size47 MB2 MB
Age rating4+4+
DeveloperEsther YekiniBenjamin Dupin

In-app purchases

3 purchases

9toFast

Subscriptions2
  • Premium Monthly$0.991 Month
  • Premium Yearly$9.991 Year
One-time1
  • Premium Lifetime$19.99
4 purchases

FastZen

One-time4
  • Coffee$0.99
  • Thanks$2.99
  • Support development$4.99
Show 1 more
  • FastZen Custom Week$5.99

Questions

Is 9toFast free?
9toFast is free to download, with in-app purchases available.
Is FastZen free?
FastZen is free to download, with in-app purchases available.
Do 9toFast or FastZen have ads?
9toFast shows ads; FastZen does not.
Which is updated more often, 9toFast or FastZen?
9toFast ships an update fortnightly, and FastZen weekly. Most recently, 9toFast was updated on October 28, 2026 and FastZen on October 28, 2026.

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