Comparison

Caffeine mg vs Caffeine Clock

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

Head to head
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?" — that's the question this app answers. ■ 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 ■ 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 ■ 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 ■ 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 ■ 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. ■ 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 ■ 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.

About

Caffeine Clock

Features
Read full description

Not how much you drank - how much is still in you now, and how much will still be there at bedtime. One tap to log Set up to four usual drinks and log them the moment you tap. Mistaps are undoable, and you can move a record to "1 hour ago" afterwards. The hours you could not see The ring at the centre - the Caffeine Halo - shows what is estimated to remain. It also shows the estimate at your bedtime and when it will be mostly gone. Connect Health (Pro) Compare the estimate at bedtime with your time asleep, night wakings, and next-morning HRV, using your records only. The analysis stays on this device and is never sent anywhere. Widgets and Apple Watch Check from the Lock Screen, Home Screen, or your watch face - and log right there. Apple Watch logs offline and syncs later without duplicates. Two themes Calm roast and crema tones, or a dark base with electric accents. Switch any time in Settings. Never blames you Days without records are not failures. No streak pressure, and notifications carry neutral wording only. No account No sign-in. Your records stay on your device. Caffeine Clock Pro (one-time purchase) unlocks sleep relations, every widget, Apple Watch, custom presets, and CSV export. Logging, estimates, the calendar, and today's and weekly stats stay free. Note: caffeine amounts shown are estimates, not measurements. Do not use them for medical, medication, or driving decisions.

Screenshots

Caffeine mg4 screens
Caffeine Clock4 screens

Verdict

The call

The clearest difference is update cadence: Caffeine Clock at every 2 days against Caffeine mg's weekly. 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. Caffeine mg sells 1 one-off in-app purchase and Caffeine Clock sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Caffeine mg ships an update weekly, Caffeine Clock every 2 days. The most recent releases landed on September 20, 2026 and September 8, 2026 respectively.

Scorecard1 real difference · 5 level
Caffeine mg versus Caffeine Clock: the parameters behind the verdict, then further details
ParameterCaffeine mgCaffeine Clock
PriceFreeFree
Update frequencyWeeklyEvery 2 days — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhoneiPhone, Apple Watch — better
Requires iOS18.018.0
Further details — not scored
Size5 MB6 MB
Age rating4+12+
Developerkensuke uedakazunari aoki

In-app purchases

1 purchases

Caffeine mg

One-time1
  • カフェむンmg Pro$1.99
1 purchases

Caffeine Clock

One-time1
  • Caffeine Clock Pro$9.99

Questions

Is Caffeine mg free?
Caffeine mg is free to download, with in-app purchases available.
Is Caffeine Clock free?
Caffeine Clock is free to download, with in-app purchases available.
Do Caffeine mg or Caffeine Clock have ads?
Neither Caffeine mg nor Caffeine Clock shows ads.
Which is updated more often, Caffeine mg or Caffeine Clock?
Caffeine mg ships an update weekly, and Caffeine Clock every 2 days. Most recently, Caffeine mg was updated on September 20, 2026 and Caffeine Clock on September 8, 2026.

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