Comparison

Eight Sleep vs Z2/4×4 Trainer

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

Head to head
About

Eight Sleep

This advanced sleep system intelligently adjusts temperature and elevation for personalized comfort. It tracks detailed sleep metrics, offering insights and recommendations to help you wake up refreshed. Supports up to two users with individual profiles and customizable wake-up features.

Highlights
  • Personalized temperature control
  • Intelligent sleep tracking
  • Autopilot for automatic adjustments
  • Sleep stage analysis
  • Customizable vibration alarm
  • Dual sleep profiles
Read full description

Introducing Pod 6. The setup is as effortless as your sleep. Guided Hub setup gets you paired in minutes, a live priming screen decodes your Pod's lights in real time so you're never guessing, and Solo Pod owners get a path built just for them. Your best sleep starts tonight. The Eight Sleep Pod is the intelligent sleep system that gives you up to one hour more of sleep every night. It cools. It heats. It elevates. PERSONALIZED SLEEP WITH AUTOPILOT Autopilot is the intelligence behind the Pod. It adjusts your temperature and elevation to perfect your sleep experience. LEARN ABOUT YOUR SLEEP AND HEALTH View your sleep stages, time slept, heart rate, HRV, and snoring. Plus, receive personalized insights and recommendations. WAKE UP REFRESHED With customizable chest-level vibration and a gradual thermal change, you will wake up gently and feel fully refreshed. TWO SLEEP PROFILES PER POD Autopilot creates a profile for up to two individuals on the same Pod and refines overtime. Have questions? We’re here to help. Email us at support@eightsleep.com. Terms of Use: - www.eightsleep.com/app-terms-conditions/ - www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Z2/4×4 Trainer

Features
Read full description

Z2/4×4 Trainer turns the two most effective endurance methods — easy Zone 2 base work and high-intensity Norwegian 4×4 intervals — into a simple daily plan built around YOUR heart rate. WHAT YOU GET • Daily and weekly Zone 2 prescriptions at 60–70% of your max heart rate to build your aerobic base. • Norwegian 4×4 sessions: four 4-minute intervals at 85–95% of max heart rate, with 3-minute recoveries — the protocol used to boost VO2 max. • Weekly health-maintenance and weight-loss targets to keep you consistent. • Personalized zones from your max heart rate (220 − age), which you can override if you know your true max. WORKS WITH APPLE HEALTH • Pull in your heart rate, resting heart rate, active energy, body weight, and past workouts — or enter everything manually. Your choice. • Completed Zone 2 and 4×4 workouts are saved back to Apple Health so all your training lives in one place. IPHONE + APPLE WATCH • Plan and review on iPhone; train with your zones on your wrist. PRIVATE BY DESIGN • 100% on-device. No account, no sign-up, no server. • Nothing you enter or that we read from Apple Health ever leaves your device. • No ads, no analytics, no tracking, no third-party SDKs. • Your Health data is never used for advertising — ever. WHO IT'S FOR • Runners, cyclists, rowers, and anyone doing cardio who wants structure instead of guesswork. • Beginners building a base and experienced athletes adding VO2-max work. FREE + AN OPTIONAL ONE-TIME UPGRADE • Everything above is free: guided workouts on iPhone and Apple Watch, plans, zones, Apple Health sync. • One optional one-time purchase (Pro) unlocks the deeper coaching analysis: full readiness breakdown, overtraining guard, adaptive weekly progression, VO2-max trend, and CSV/JSON export. No subscription. Z2/4×4 Trainer is a fitness and training tool, not a medical device. It does not diagnose, treat, or prevent any disease. Talk to a healthcare professional before starting a new exercise program.

Screenshots

Eight Sleep4 screens
Z2/4×4 Trainer4 screens

Verdict

The call

The clearest difference is update cadence: Eight Sleep at every 4 days against Z2/4×4 Trainer's every 3 weeks. 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. Eight Sleep sells 2 in-app purchases, starting at $18.99 per month and Z2/4×4 Trainer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Eight Sleep ships an update every 4 days, Z2/4×4 Trainer every 3 weeks. The most recent releases landed on November 11, 2026 and November 10, 2026 respectively.

Scorecard1 real difference · 9 level
Eight Sleep versus Z2/4×4 Trainer: the parameters behind the verdict, then further details
ParameterEight SleepZ2/4×4 Trainer
PriceFreeFree
Rating4.8 (18K ratings) — better—
Positive reviews28.7% of reviews—
Number of ratings18K — better—
Update frequencyEvery 4 days — betterEvery 3 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFreemium—
DevicesiPhone, iPadiPhone, Apple Watch
Requires iOS18.018.0
Further details — not scored
Size265 MB5 MB
Age rating12+4+
DeveloperEight Sleep, IncChenfei Chu

Bugs and requests

Eight Sleep

Reported bugs

5 issues
  • App freezes and loses connection to pod
  • Alarms not working or turning off properly
  • Temperature settings not saving or resetting
  • Sleep data not syncing or displaying accurately
  • Frequent app crashes and performance issues

Requested features

5 requests
  • Apple Watch app integration
  • Offline temperature/alarm controls
  • Customizable sleep tracking and insights
  • Improved alarm snooze/dismiss functionality
  • Nap mode and more sleep schedule flexibility

Z2/4×4 Trainer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Eight Sleep

Subscriptions2
  • 8+ Pro (Monthly)$18.991 Month
  • 8+ Pro (Annual)$179.991 Year
1 purchases

Z2/4×4 Trainer

One-time1
  • Z2/4×4 Pro (Lifetime)$14.99

Questions

Is Eight Sleep free?
Eight Sleep is free to download, with in-app purchases available.
Is Z2/4×4 Trainer free?
Z2/4×4 Trainer is free to download, with in-app purchases available.
Do Eight Sleep or Z2/4×4 Trainer have ads?
Neither Eight Sleep nor Z2/4×4 Trainer shows ads.
Which is updated more often, Eight Sleep or Z2/4×4 Trainer?
Eight Sleep ships an update every 4 days, and Z2/4×4 Trainer every 3 weeks. Most recently, Eight Sleep was updated on November 11, 2026 and Z2/4×4 Trainer on November 10, 2026.

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