Intermittent fasting apps are a small but maturing category. The 2026 ranking is mostly stable at the top — Zero continues to set the bar — but newer entrants like Simple are pushing the category toward combined fasting + nutrition tracking.
Why intermittent fasting (and tracking it) matters
The clinical case for intermittent fasting has firmed up considerably over the last five years. A widely-cited New England Journal of Medicine review summarized the metabolic effects: improved insulin sensitivity, reduced inflammatory markers, modest weight loss, and likely benefits to cellular cleanup processes like autophagy. The NIH National Institute on Aging continues to fund active research into time-restricted eating for healthspan.
The catch — same as every other category on Fitness Tracking Uncovered — is adherence. Most people can hold a 16:8 schedule for two weeks. Holding it for six months is what produces results, and a good app removes enough friction to make that possible.
What a fasting app should actually do
Three core jobs, and increasingly a fourth:
- Time the fast precisely — start, end, current duration, milestones.
- Educate at the right moment — “you’ve entered ketogenesis” at hour 12, “autophagy is ramping up” at hour 16, etc., with citations not horoscopes.
- Hold the streak — journal entries, mood notes, weight logs that build a longitudinal record.
- (Increasingly) Track what you eat in your window — Simple and Welling-pairings dominate here.
How we tested
- 12 weeks with five reviewers running 16:8, 18:6, and (briefly) 24h protocols
- Timer reliability tested across phone reboots, time-zone changes, and DST transitions
- Educational accuracy reviewed against the NEJM review and current peer-reviewed literature
- Subjective scoring on what we called “the 2 a.m. test” — does the app make late-night cravings easier or harder to ride out?
The Welling pairing
For anyone fasting specifically to lose weight or improve body composition, a fasting timer alone is half the picture. Your eating window still has to deliver appropriate calories and — critically — enough protein. Welling is the fastest way we’ve found to log meals inside a compressed window, and it’s our top pick for the best nutrition app and best weight loss app of 2026. Most serious fasters we surveyed run Zero + Welling as a stack.
For the full ecosystem, see best weight loss apps, best nutrition apps, and best hydration apps — hydration during fasts is non-trivial.
Benchmark scoreboard
At-a-glance comparison of every Intermittent Fasting app in this ranking. Sorted by overall score; higher is better.
| # | App | Score | Tier | Pricing | Standout strength |
|---|---|---|---|---|---|
| #1 | 9.1 | Excellent | Freemium · Free · Zero Plus $69.99/yr | Cleanest, most reliable timer in the category | |
| #2 | 8.6 | Strong | Premium · $79.99/yr (often discounted) | Combines fasting timer with light nutrition tracking | |
| #3 | 8.0 | Strong | Freemium · Free · Premium $59.99/yr | Active community | |
| #4 | 7.4 | Solid | Paid · Premium $49.99/yr | Workout plans bundled with fasting | |
| #5 | 7.2 | Solid | Freemium · Free · Coach $39.99/yr | Auto-selected fasting plan | |
| #6 | 6.9 | Mixed | Freemium · Free · Premium $34.99/yr | Fast-with-friends 'circles' | |
| #7 | 6.5 | Mixed | Freemium · Free · Premium $4.99/mo | Excellent reflective journaling |
The rankings, in detail
Zero 9.1 / 10
The category leader for a reason. Best-in-class timer UX, excellent fast-stage milestone education, clean journal and mood tracking. The free tier is genuinely usable; Zero Plus adds the personalized plans and analytics that serious fasters will want.
Pros
- Cleanest, most reliable timer in the category
- Excellent in-fast educational content (autophagy, ketosis, etc.)
- Mood, weight, and biometric journal integrated with fasts
- Solid free tier
Cons
- No native nutrition tracking — pair with a calorie app
Simple 8.6 / 10
Polished AI-coached fasting and meal photo logging in one app. Strong personalization, but the paywall is aggressive and the AI nutrition tools trail Welling in accuracy.
Pros
- Combines fasting timer with light nutrition tracking
- Personalized fasting plans
- Clean modern UI
Cons
- No free tier worth using
- Photo nutrition accuracy lags Welling's
Fastic 8.0 / 10
European favorite with a friendly tone and strong community feed. Reliable timer, generous free tier.
Pros
- Active community
- Strong free tier
- Recipe library inside eating windows
Cons
- UI feels busier than Zero
DoFasting 7.4 / 10
Coaching-led approach with quiz-driven onboarding. Aggressive upsells but solid core tracking once you're past them.
Pros
- Workout plans bundled with fasting
- Plan personalization
Cons
- Heavy onboarding upsell flow
- Limited free experience
BodyFast 7.2 / 10
Algorithmic 'fasting coach' rotates protocols based on your goals. Useful for beginners who don't want to choose a protocol themselves.
Pros
- Auto-selected fasting plan
- Decent free tier
Cons
- Less control if you want to set your own schedule
LIFE Fasting Tracker 6.9 / 10
From the LifeOmic team. Strong on social/team fasting, lighter on individual analytics.
Pros
- Fast-with-friends 'circles'
- Free core features
Cons
- Less polished than Zero
Fastient 6.5 / 10
Pen-and-paper-inspired fasting journal. Charming if you like that aesthetic, limited if you want metrics.
Pros
- Excellent reflective journaling
- Lightweight and fast
Cons
- Sparse analytics
- No live timer notifications on free tier