Comparison

Fast36 vs Fasting Well

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

Head to head
About

Fast36

Features
Read full description

Stages, not streaks. Fast36 is the fasting app for people who care about the metabolic arc, not the calendar grid. Track the biochemical progression of a 24 to 72+ hour fast with phase-aware timing, in-the-moment science, and a private record of every session. WHAT YOU GET • Stage-aware timer. Watch your fast move through the four metabolic regimes — glycogen depletion, ketosis, autophagy, deep autophagy — with color-coded thresholds that match real human physiology. • Quick Log for ketones and glucose. Pair every fast with a finger-stick reading. Build a longitudinal record of how your biomarkers respond to each protocol. • Live Activity on the Lock Screen. Current stage, elapsed time, and next threshold — always one glance away. No need to open the app. • Apple Watch companion. Start, monitor, and end fasts from your wrist. Phone, iPad, and watch always show the same session. • History with substance. Total hours, per-stage distribution, per-fast gantt, readings, notes. No streaks. No flame emoji. No celebratory confetti. • The Science reference. Peer-reviewed citations for every stage claim. We tell you what's proven in humans and what's extrapolated from rodent studies, and when evidence is emerging rather than settled. FREE • 36-hour protocol — the namesake fast • Stage-aware timer and Stages reference • History log and HealthKit integration • On-device privacy FAST36 PRO — $14.99 / month or $99 / year • 24-hour reset fasts • 48-hour and 72-hour extended protocols • Custom fast lengths • Live Activity with stage transitions • Stage-crossing haptics • Apple Watch companion • Quick Log for ketones and glucose • Full history analytics and stage distribution chart • Notes on every fast • Apple Health bidirectional sync • The Science deep-dive with citations WHO IT'S FOR Biohackers running 24 / 36 / 48 / 72-hour protocols. People who want their fasting app to read like a lab notebook, not a game. Anyone who has ever said "autophagy" at dinner and meant it. Not for calorie counting, not for weight-loss streaks, not for "gamified wellness." PRIVACY All fasting data lives on-device. Optional Apple Health sync stays between you and Apple — it does not pass through our servers. No accounts, no newsletters, no behavioral tracking, no third-party analytics. Not medical advice. Extended fasting carries real risks for people with diabetes, eating disorder history, pregnancy, low body fat, or on medications affecting blood sugar or blood pressure. Consult a clinician before attempting any fast over 24 hours. Fast36 Pro subscriptions renew automatically unless cancelled at least 24 hours before the current period ends. Manage or cancel from your Apple ID settings. Terms of Use: https://fast36.app/terms Privacy Policy: https://fast36.app/privacy Support: hello@fast36.app

About

Fasting Well

Track your intermittent fasting journey with science-backed insights. Monitor your progress through different metabolic stages and view your history with a visual heatmap. Offers built-in plans and detailed scientific articles.

Highlights
  • Stage-aware fasting progress visualization
  • Live timer with customizable ring
  • Six built-in fasting plans
  • Journal and weekly progress charts
  • Science-backed articles on fasting
  • Calendar heatmap of activity
  • Privacy-first, on-device data storage
Features
Read full description

Fasting Well is a beautiful, science-grounded intermittent fasting tracker. Designed for the moments your fast actually happens — at home, in transit, before bed — with the kind of polish you'd expect from an app you open every day. EVERY FAST IS A JOURNEY A fast isn't a single state — it's a sequence. Anabolic. Catabolic. Fat-burning. Ketosis. Deep ketosis. Fasting Well shows you exactly where you are in that journey, with stage-aware visuals and a quiet narration of what's happening inside. WHAT YOU GET (FREE) • Live timer with the ring you'll want to watch • Six built-in plans: 16:8, 18:6, 20:4, OMAD, 24h, 36h • Stage-aware progress: see Anabolic → Ketosis unfold • Notifications when you cross a stage or hit your goal • Journal of your last 30 days with a weekly chart • Five long-form science articles, beautifully illustrated • Calendar heatmap of recent activity • Dark and light themes that look right on every screen WHY ANOTHER FASTING APP Because the popular ones either gutted their free tier or never felt like apps you'd open without a reason. Fasting Well is built to be the home screen icon you actually like seeing. PRIVACY-FIRST Your fasts and weight data stay on your device — no account, no cloud sync, no servers we own. To make the app better we collect anonymous usage signals (e.g. "a fast was started on the 18:6 plan" or "an article was opened") through PostHog. These contain no personally identifying information and can be turned off entirely in Settings → Privacy. SCIENCE-BACKED, NOT WELLNESS-HYPE Built on peer-reviewed fasting research. No talk of "detox." No supplements to sell. Just the metabolic story your body is actually telling. FASTING WELL PRO Go deeper with Pro: build custom fasting protocols, log your weight and watch the trend, unlock advanced statistics (12-week heatmap, completion rate, best streak), share beautiful fast cards, and pick from every accent color. Pro is a monthly or annual subscription, or a one-time lifetime purchase — and the core tracker stays free forever. QUESTIONS, FEEDBACK hello@fastingwell.app We're a small team. Every email gets read. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://fastingwell.app/privacy

Screenshots

Fast364 screens
Fasting Well4 screens

Verdict

The call

The clearest difference is in-app purchases: Fasting Well at none against Fast36's 2. On price, ads, device support and iOS requirement 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. Fast36 sells 2 in-app purchases, starting at $14.99 per month. Fasting Well asks for nothing beyond the download.

Scorecard1 real difference · 9 level
Fast36 versus Fasting Well: the parameters behind the verdict, then further details
ParameterFast36Fasting Well
PriceFreeFree
Rating—5.0 (2 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—2 — better
Update frequency—Every 3 months
AdsNoNo
In-app purchasesYesNo — better
Monetization—Freemium
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size7 MB45 MB
Age rating4+4+
DeveloperAKN Technologies FZ-LLCGeneralizable

In-app purchases

2 purchases

Fast36

Subscriptions2
  • Fast36 Pro - Monthly$14.991 Month
  • Fast36 Pro - Yearly$99.991 Year
None

Fasting Well

No in-app purchases

Questions

Is Fast36 free?
Fast36 is free to download, with in-app purchases available.
Is Fasting Well free?
Fasting Well is free to download, with no in-app purchases.
Do Fast36 or Fasting Well have ads?
Neither Fast36 nor Fasting Well shows ads.

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