You don’t need to pay for a fasting app.

But you also don’t want one that shows ads every time you check your timer.

I tested the most popular free fasting apps. Here’s what’s actually worth downloading.

Quick Comparison

AppFree TierAdsBest FeatureRating
FastTrackFull featuresNoClean timer + zones⭐⭐⭐⭐⭐
ZeroLimitedNoCommunity⭐⭐⭐⭐
FasticVery limitedYesGamification⭐⭐⭐
SimpleLimitedSomeMeal suggestions⭐⭐⭐
Life FastingCore featuresNoCircles (social)⭐⭐⭐⭐

The Best Free Options

1. FastTrack

Price: Free Ads: None

I built this one, so yes, I’m biased. But I built it because the free options were frustrating.

What you get free:

  • Unlimited fasting timers
  • Fasting zones visualization (fat burn, ketosis, autophagy)
  • Custom fasting schedules
  • Apple Watch app
  • Streak tracking
  • Apple Health sync

What it does right:

  • One tap to start/end
  • Clean visual showing exactly where you are in your fast
  • No features locked behind paywall
  • No ads interrupting your timer

What could be better:

  • Newer app (fewer reviews)

Download →

2. Zero

Price: Free (Premium $70/year) Ads: None

The most popular fasting app. Made by the guy who coined “bulletproof coffee.”

What you get free:

  • Basic timer
  • Limited fasting history
  • Limited insights

What’s locked:

  • Fasting zones visualization
  • Advanced stats
  • Coach feature
  • Most useful insights

Verdict: Good, but the best stuff is paywalled. $70/year is steep.

3. Life Fasting Tracker

Price: Free (Premium available) Ads: None

Best known for “Circles” — group fasting with friends.

What you get free:

  • Fasting timer
  • Basic stats
  • Circles (social fasting)
  • Some zone tracking

What’s locked:

  • Advanced insights
  • Detailed analytics

Verdict: Great if you want to fast with friends. Otherwise, basic.

4. Fastic

Price: Free (Premium $12/month) Ads: Yes

Very gamified. Quests, achievements, challenges.

What you get free:

  • Basic timer
  • Some gamification elements
  • Recipes

What’s locked:

  • Detailed fasting tracking
  • Meal plans
  • Most features

What’s annoying:

  • Constant upsells
  • Premium prompts every session
  • Ads

Verdict: Fun if you like gamification. Aggressive monetization.

5. Simple: Intermittent Fasting

Price: Free trial, then subscription Ads: Some

Focuses on the “why” — lots of educational content.

What you get free:

  • Basic timer
  • Some tips
  • Limited tracking

What’s locked:

  • Full fasting features
  • Meal tracking
  • Insights

Verdict: Basically a trial. Pushes you to subscribe quickly.

What to Look For in a Free Fasting App

Must-have features:

  1. Reliable timer — Sounds obvious, but some apps don’t count background time correctly
  2. Start/stop with one tap — No 4-screen navigation
  3. Fasting zones — Know when you hit fat burning vs autophagy
  4. History — See your past fasts

Nice to have:

  • Apple Watch app
  • Widget for home screen
  • Apple Health sync
  • Streak tracking

Red flags:

  • Ads on the timer screen (you’ll look at this 10x a day)
  • Basic features paywalled
  • Subscription required for core functionality
  • Constant upsell prompts

The Hidden Costs of “Free”

Many “free” fasting apps:

  • Show ads every time you open them
  • Lock basic features after 7 days
  • Require subscription for history beyond 1 week
  • Push premium constantly

A truly free app should let you track your fast without interruption. That’s the minimum.

Do You Even Need an App?

Honestly? You could use your phone’s built-in timer.

But a fasting app:

  • Tracks your progress over time
  • Shows fasting zones so you know what’s happening in your body
  • Motivates with streaks
  • Reminds you when your window opens/closes

If you’re serious about fasting, an app helps. If you’re just trying it once, set a timer.

FAQ

Which fasting app is completely free? FastTrack and Life Fasting offer the most features for free. Zero’s free tier is very limited.

Is Zero worth paying for? If you want detailed insights and coaching, maybe. $70/year is expensive for a timer.

Can I use Apple Health to track fasting? Not directly. Apple Health doesn’t have a fasting category. You need an app.

What’s the best fasting app for beginners? One with clear fasting zones so you understand what’s happening. FastTrack or Zero’s free tier.

Do I need the premium version of any fasting app? No. Basic fasting tracking doesn’t require premium features.

Related reads:

— Dolce