Comparison

HalfCaff vs Caffeine mg

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

Head to head
About

HalfCaff

Features
Read full description

HalfCaff tracks your caffeine intake and shows exactly how much caffeine is in your body right now. Using scientifically-based half-life calculations, HalfCaff answers the one question every coffee lover asks: "Can I have another cup and still sleep tonight?" "โ—‹โ—‹mg remaining" โ€” Based on your bedtime threshold and the FDA daily limit (400mg), see exactly how much more you can drink at a glance. Features: - Real-time body caffeine level with circular gauge - Remaining allowance display ("โ—‹โ—‹mg OK to drink") - 24-hour caffeine decay curve - 70+ drink presets (Starbucks, Doutor, Tully's official data) - Home screen widgets (Small & Medium) - Dynamic Island & Live Activities - Personalized half-life based on your caffeine sensitivity HalfCaff Pro unlocks: - Home screen widgets - Dynamic Island display - Unlimited history Includes a 3-day free trial. Terms: https://halfcaff.decoy284.net/terms/ Privacy Policy: https://halfcaff.decoy284.net/privacy/

About

Caffeine mg

Features
Read full description

Caffeine mg is a one-tap caffeine tracker that visualises remaining body caffeine and the time it drops below a sleep-friendly threshold using a half-life decay model. "Can I have one more coffee this afternoon and still sleep tonight?" โ€” that's the question this app answers. โ–  Who it's for - Daily coffee or energy drink consumers - People whose afternoon caffeine affects sleep - Users who prefer no ads and one-time purchases - Login-free tracking with caffeine records stored on device โ–  Main features - 50+ preset drinks (coffee, energy drinks, tea, etc.) - Custom drinks with caffeine content and serving size - Tap to log "now", long press to set the time - Today's total intake and remaining allowance (400mg default) - Half-life decay simulation - Home screen widget for one-tap logging - Siri / Shortcuts support - Last 7 days of history โ–  iOS 18 features (Pro) - Live Activity + Dynamic Island for body caffeine + sleep-friendly time - Lock Screen Control + Control Center for one-tap logging - Action Button on iPhone 15 Pro and later - Half-life simulation chart โ–  Pro (one-time, JPY 370) - Unlimited custom drinks - Live Activity / Dynamic Island - Lock Screen Control - Action Button integration - Full history + CSV export - Medium / Large widgets โ–  Why we made it - Free to start (50+ presets + 3 custom drinks) - No login, no account - Caffeine records stay on device; anonymous usage events are optional - No subscription. Pro is one-time only. - Zero ads. โ–  Science - Daily upper limit 400 mg (WHO / FDA / EFSA / Health Canada / Japan MHLW Sleep Guidelines 2023 consensus) - 50 mg "sleep-friendly residual" threshold per Japan MHLW Sleep Guidelines 2023 - Default half-life is 5 hours (individual range 3-7 hours) - All thresholds adjustable in Settings โ–  Requirements - iOS 18.0 or later (for Live Activity / Lock Screen Control / Action Button) This app is intended as a caffeine intake tracker. It does not provide medical advice, diagnosis, drug-interaction checks, or individualised guidance for pregnant users, users with cardiac conditions, etc. Please consult a doctor or pharmacist for health decisions.

Screenshots

HalfCaff4 screens
Caffeine mg4 screens

Verdict

The call

HalfCaff and Caffeine mg are too close to call on the numbers: across 6 compared parameters โ€” price, update cadence, ads and in-app purchases among them โ€” neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. HalfCaff sells 3 in-app purchases, starting at $1.99 per 7 days and Caffeine mg sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

HalfCaff ships an update every 6 days, Caffeine mg weekly. The most recent releases landed on July 4, 2026 and September 20, 2026 respectively.

ScorecardNo meaningful differences
HalfCaff versus Caffeine mg: the parameters behind the verdict, then further details
ParameterHalfCaffCaffeine mg
PriceFreeFree
Update frequencyEvery 6 days โ€” betterWeekly
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad โ€” betteriPhone
Requires iOS17.0 โ€” better18.0
Further details โ€” not scored
Size4 MB5 MB
Age rating4+4+
DeveloperYutaro Koidekensuke ueda

In-app purchases

3 purchases

HalfCaff

Subscriptions3
  • Weekly3 Days trial$1.997 Days
  • Monthly3 Days trial$5.991 Month
  • Yearly3 Days trial$22.991 Year
1 purchases

Caffeine mg

One-time1
  • ใ‚ซใƒ•ใ‚งใ‚คใƒณmg Pro$1.99

Questions

Is HalfCaff free?
HalfCaff is free to download, with in-app purchases available.
Is Caffeine mg free?
Caffeine mg is free to download, with in-app purchases available.
Do HalfCaff or Caffeine mg have ads?
Neither HalfCaff nor Caffeine mg shows ads.
Which is updated more often, HalfCaff or Caffeine mg?
HalfCaff ships an update every 6 days, and Caffeine mg weekly. Most recently, HalfCaff was updated on July 4, 2026 and Caffeine mg on September 20, 2026.

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