Caffeine Half Life vs Caffy
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Caffeine Half Life
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Caffeine Half Life helps you estimate how caffeine leaves your system over time — so you can make more informed choices about sleep and energy. Highlights - Personalized elimination curve using your profile (e.g. smoking, pregnancy, oral contraceptives) when you choose to provide them - Sleep-readiness estimates based on your bedtime and caffeine threshold — approximate only - Apple Health: optional read/write for dietary caffeine, plus HRV correlation on the chart so you can spot patterns (you control permissions) - Widgets and Apple Watch complications for quick glances — including a trend graph complication - Interactive chart — drag to inspect caffeine levels and HRV at any time of day How it works The app uses a simplified pharmacokinetic model (Bateman equation) to estimate caffeine absorption and elimination based on your personalized half-life. Factors like age, BMI, activity level, smoking, pregnancy, and oral contraceptives adjust the half-life up or down from the ~5-hour population average. Important: This app is for general wellness and educational purposes. It is not medical advice and not a medical device. All estimates are approximate — individual metabolism varies. Consult a healthcare professional for health decisions. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Caffy
Track your caffeine intake and understand its impact on your sleep and productivity. This app uses science-backed models to provide personalized insights into your caffeine levels and when you'll be ready for sleep.
- Real-time caffeine decay curve
- Personalized sleep readiness score
- Focus window for productivity peaks
- AI weekly analysis of caffeine patterns
- Caffeine detox programs
- Live home screen widgets
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Caffy shows your exact caffeine level right now, and tells you precisely when you'll be ready to sleep tonight. Using pharmacokinetic half-life models backed by FDA, EFSA & NIH research, Caffy calculates your personal caffeine curve based on your biology. WHAT MAKES CAFFY DIFFERENT: • Real-time caffeine decay curve: personalized to your age, gender & sensitivity • Sleep readiness score (0–100): know if tonight's sleep is at risk before bedtime • Focus window: see exactly when your caffeine peaks for maximum productivity • AI Weekly Analysis: AI reveals your personal caffeine patterns • Caffeine Detox Programs: structured plans to reduce dependence gradually • 6 Live Widgets: caffeine data on your Home Screen and Lock Screen • 5 Languages: English, Turkish, German, Spanish, Japanese PERSONALIZED HALF-LIFE: Your body processes caffeine differently. Caffy accounts for: • Pregnancy (9h / 12h / 18h half-life) • Oral contraceptive use (7h half-life) • Smoking status (3h half-life) • Age, gender & caffeine sensitivity SCIENCE-BACKED: Caffy's model uses the same caffeine decay formula cited by FDA, EFSA, NIH, and the Sleep Foundation. Not estimates, not averages. A 45-minute absorption phase followed by exponential decay based on your personal half-life. PRIVACY FIRST: No ads. No data selling. Anonymous by default: no registration required on first launch. Your data syncs across devices via an encrypted, GDPR-compliant database. DISCLAIMER: All estimates are based on generalized scientific models and do not constitute medical advice. Consult a healthcare professional for personalized guidance. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is update cadence: Caffeine Half Life at every 5 days against Caffy's every 2 weeks. Caffeine Half Life also leads on device support (3 vs 1). Caffy's advantage is iOS requirement (18.6 vs 26.0). On price, 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
Both are free to download. Caffeine Half Life sells 1 in-app purchase, starting at $1.99 per month and Caffy sells 3 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.
Caffeine Half Life ships an update every 5 days, Caffy every 2 weeks. The most recent releases landed on October 25, 2026 and October 23, 2026 respectively.
| Parameter | Caffeine Half Life | Caffy |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 5 days — better | Every 2 weeks |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Freemium |
| Devices | iPhone, iPad, Apple Watch — better | iPhone |
| Requires iOS | 26.0 | 18.6 — better |
| Further details — not scored | ||
| Size | 13 MB | 27 MB |
| Age rating | 12+ | 12+ |
| Developer | Adrian Nowak | Irfan Behic TIRPANCI |
In-app purchases
Caffeine Half Life
- Premium$1.991 Month
Caffy
- Caffy Premium3 Days trial$2.997 Days
- Caffy Premium3 Days trial$6.991 Month
- Caffy Premium3 Days trial$29.991 Year









