Best Free Fasting Apps (and What to Check Before You Pay)

The best free fasting app is the one that does the few things you need without asking for an account or a subscription before you can start. For most people on a plan like 16:8, that means a timer, a reminder when the window opens or closes, and a simple history. Several apps do this well, some locked behind a paid tier, and you may not need an app at all.

This guide is written by the makers of Fastly, so keep that in mind as you read. We include Fastly as one option, say where it falls short, and point you to other apps when they fit better. Everything we say about other apps comes from their own store pages, checked on October 19, 2026. Store listings change, so look at the current page before you download.

What a fasting app actually has to do

Intermittent fasting is a way of setting the hours you eat and the hours you don't. A common version is 16:8, which means 16 hours without food and an eight-hour eating window. Other popular patterns are 18:6, 20:4 and OMAD (one meal a day). If you want the details of one pattern, our 16:8 schedule guide walks through example windows.

An app only has to help with the practical side of that:

• Tell you when the fast started, and let you fix the time if you forgot to tap.
• Tell you when the window opens, so you don't have to watch the clock.
• Keep a record, so you can see whether you were consistent.

Anything beyond that, such as meal photos, coaching or recipes, is extra. Some people like extras. Many people on Reddit say they just want a timer that gets out of the way, and that they feel tired of apps that push subscriptions and ads (one r/intermittentfasting thread asks about exactly this). If that's you, the checklist below will save you some time.

Do you need an app at all?

Not necessarily. If you eat dinner at 7 pm and your window opens at 11 am, your phone's clock app and one alarm do the job. A notes file or a paper calendar can hold your history.

Before you install anything, try our two free tools. They run in your browser and need no sign-up:

• The fasting schedule calculator turns your plan plus your wake-up and sleep times into an eating window and a fasting window, shown on a 24-hour ring. You can print it and stick it on the fridge.
• The when can I eat timer takes the time your last meal ended and your plan, then shows how long until your window opens.

An app starts to earn its place when you want one-tap tracking, reminders that arrive without you setting alarms, a streak to keep you honest, or a home screen widget. If those matter, read on.

A checklist before you install or subscribe

Use these questions on any fasting app, including ours. Most answers are on the store page, under the description, the in-app purchases list and the App Privacy section.

Do you have to make an account first?

Some apps let you start a fast right away. Others ask you to sign in or answer a long quiz before you see a timer. An account isn't automatically bad, since it can sync across devices. But if you only want a timer, a sign-up wall is a cost.

Apple requires every app to list what data it collects in a privacy section on its store page, and you can read it before you download. Apple explains what those labels mean in its App Privacy details page. Two things to look for: whether a user ID or email is collected, and whether data is used for advertising.

What stays free?

"Free to download" often means the timer is free and something else isn't. Common paywalled items are the full history, charts, custom fasting times, extra plans and exports. Check the list of in-app purchases and the description for phrases like "unlock" or "Plus" or "Premium".

A free history that only goes back a few entries is a different deal from a history that keeps everything. Ask yourself whether the thing behind the paywall is something you'd actually use.

Is there a free trial that turns into a charge?

Many apps offer a trial, then bill you automatically. Know how to cancel before you start. Apple explains how to cancel a subscription billed by Apple, and Google explains how to cancel, pause or change a subscription on Google Play. Set a calendar reminder for the day before a trial ends.

Are there ads?

The store page won't always say so. A "Contains Advertising" label in the age rating section, and data "used for advertising" in the privacy section, are hints. A fasting timer that stays on screen all day is a prime spot for ads, so it's worth checking.

Does it work offline, and where is your data?

A fasting timer needs no internet. If an app stores your fasts on the phone, it keeps working on a plane, and nothing about your eating habits has to leave your device. If it stores everything in an account, your history lives on someone's server. Neither is wrong, but you should know which you're getting.

Does it have reminders and a widget?

Reminders for when the window opens and closes are the main reason many people use an app. A home screen or lock screen widget saves you from opening the app to see the time. Not every app has one, so confirm on the page if it matters to you.

Do the health claims sound too good?

Fasting research is mixed. Harvard Health's overview of a one-year trial found that an eight-hour eating window gave about the same weight loss as cutting calories without a window, and it notes that intermittent fasting isn't safe for everyone. You can read it in Intermittent Fasting for Weight Loss: What the Evidence Shows. Be wary of any app that promises a number of pounds, a "fat burning" hour or a "detox".

Free fasting apps compared

The table summarizes what each app's own store or website says. It uses no star ratings or prices, because those vary by country and change often. Where a page doesn't say something, the table says "not stated", which isn't the same as "no".

App	What the page says is free	What the page says needs a paid tier	Account	Widget
Zero	Fasting timer, weekly trends, a timeline of daily logs	Photo meal logging, water tracking, custom fasts, monthly and yearly charts	Not stated	Yes
Fastic	Free to download with in-app purchases	Full access, personalized plan and nutrition guide	Not stated	Not stated
BodyFast	Timer with reminders, 10+ plans, weight and water tracking	Coach features	Not stated	Not stated
Window	Timer, reminders, weight journal, water tracker	Personalized program, all fasting plans, meal plans	Not stated	Not stated (Watch complications)
Simple	Free version with an AI coach, habit trackers, nutrition scores	Daily check-ins and the education library	Yes	Not stated
Fastly	Timer, presets, custom goal, streak, weight and water logs, reminders, widget	Full history beyond the last few fasts, CSV export	No	Yes

Now a closer, fair look at each.

Zero

Zero is one of the best-known fasting apps, and its store page presents it as an all-in-one fasting and nutrition tracker. It tracks fasting alongside protein, meals, hydration and daily habits such as sleep and mood, and it includes articles and challenges.

The listing says it's free to download with an optional subscription called Zero Plus, which has a free trial. According to the page, Plus unlocks things such as photo meal logging, the Protein Score, water tracking, custom fasts and monthly and yearly charts. Weekly trends are free. It has a fasting widget, and the listing also mentions Apple Watch complications.

Who it fits: people who want fasting and food tracking in one place and don't mind a paid tier for the extras. Who might look elsewhere: people who want custom fasting hours or water tracking without subscribing, since the page lists those under Plus. People on Reddit often ask whether there is something better than Zero (here's one such thread), and the answer depends on whether you want more features or fewer.

Fastic

Fastic leans toward weight loss and nutrition. The listing mentions a fasting timer with stage information, a food scanner, a calorie and nutrition tracker, a protein fasting mode with recipes, a water tracker with reminders, Apple Health sync, challenges and an AI chat. It's free to download with in-app purchases, and a paid tier called Fastic PLUS is sold in 1-, 3- and 12-month terms. The listing says full access, including the personalized plan and nutrition guide, requires a purchase.

The page doesn't say whether you need an account, but the privacy section lists a user ID. The age rating section carries a "Contains Advertising" label.

Who it fits: people who want guided plans, recipes and nutrition tracking, and are happy with a subscription. Who might look elsewhere: people who want a plain timer. Fastic is built to do more than that.

BodyFast

BodyFast pairs a free timer with a paid coach. The listing says the free side includes a fasting timer with reminders, a set of customizable fasting plans, weight and body measurement tracking, a water tracker, fasting-stage information and a knowledge section. The Coach subscription adds a weekly plan from the coach, daily coaching, recipes, food facts and weekly challenges. The page doesn't mention a widget, and it doesn't say whether an account is required.

The store page counts the free plans two different ways (more than 10 in the feature list, 50+ in a developer reply), so check the app itself if the number matters to you.

Who it fits: people who want coaching and a structured plan, with a usable free timer to start. Who might look elsewhere: people who just want to log fasts and aren't interested in a coach.

Window

Window on iOS is a fasting and eating timer. Its free features, per the listing, are the timer, reminders when windows open or close, a weight journal with a goal, a water tracker, a health blog and sync with Apple Watch and Apple Health. Premium adds a personalized program, all fasting plans, meal plans, personal statistics, challenges and a nutrition and mood tracker.

The listing doesn't mention an iPhone widget, though release notes describe Apple Watch complications. Privacy labels list a user ID and email address, and data used to track users across other companies' apps, so read that section before installing. One reviewer on the page complained about a limit on reopening a closed window, and the developer replied that the subscription is optional.

Who it fits: Apple Watch users who want reminders and weight and water logs without paying. Who might look elsewhere: people who want every plan unlocked for free, since the listing puts "all fasting plans" under premium.

Simple

Simple is closer to a weight management coach than a pure timer. Its website describes an intermittent fasting schedule matched to your goals, a personalized plan, food logging with a scanner, water and habit trackers, and an AI coach called Avo. It says a free version includes real-time answers from Avo, nutrition scores and habit trackers, and that Premium adds daily check-ins and an educational library. The site says you need a Simple account to get started.

The page we read doesn't clearly describe a fasting timer, so if a timer is all you want, check the app itself first.

Who it fits: people who want an AI coach and a broader plan. Who might look elsewhere: anyone who wants to start a fast in one tap with no sign-up.

Smaller, simpler apps

If the larger apps feel like too much, there are small fasting timers made by independent developers. One we looked at is Simple Fasting App (not to be confused with Simple from Simple.Life). Its listing says it's free to use, without ads or subscriptions. It offers 12:12, 16:8, 18:6, 20:4 and 24-hour fasts plus a custom duration, widgets, Live Activities, Apple Watch support, a history with averages, and stage guides described as general estimates. The privacy section says no data is collected, which Apple notes is self-reported. It requires iOS 17.6 or later, so older iPhones are out.

We haven't used it ourselves, so treat this as what the store page says. The point is that an app with a very small feature list and no paywall exists, and a search for "fasting timer" will turn up more like it. Look at the developer, the privacy section and the update history before you trust one with your routine.

Where Fastly fits

Fastly is a simple fasting tracker for iPhone and Android, and its pitch is that it keeps the basics free and asks for nothing up front. Here is what it has, based on how the app works today:

• One-tap timer. Tap Start Fast and a progress ring counts your time. You can adjust the start time if you began earlier than you tapped, then tap End Fast when you eat.
• Plans. Presets for 12:12, 14:10, 16:8, 18:6, 20:4 and OMAD (23:1), plus a custom fasting goal.
• Streak and activity. A streak card, a weekly activity chart and fasting stats.
• Weight and water logs. Log your weight against a goal and a daily water target, with charts.
• Reminders and a widget. Notifications for your fast, plus a home screen widget.
• Fasting stages. A card showing the stages people commonly describe at each hour. It's educational only and isn't a measurement of your body.
• No account. There is no sign-up and no email. Your data is stored on your phone and the app works offline. Crash reports go to Firebase Crashlytics, and purchases go through RevenueCat.

Fastly is free to download. Some features, including your full fasting history and CSV export, need Fastly Pro. On the free side you see your last few fasts in history. If you want a long record or an export you can open in a spreadsheet, you'd need Pro.

What Fastly doesn't do

Being fair means saying this plainly:

• It has no coach, no recipes and no meal or calorie logging. If you want those, Fastic, BodyFast or Zero are built for it.
• It has no sync across devices, because there is no account. Your data lives on one phone.
• The fasting stages are general and shouldn't be read as what is happening in your body.
• It makes no promise about weight loss. As the Harvard summary above says, timing by itself may add little beyond eating fewer calories, and results differ between people.

A quick way to choose

If you want one answer, here it is by situation:

1. You only want to hit 16:8 and see a streak. Start with the free tools above, or a timer-first app such as Fastly or a small independent one. You can compare them in an evening.
2. You want food and nutrition tracking too. Zero or Fastic are built around that. Expect a subscription for the full set.
3. You want coaching. BodyFast or Simple, with the same caveat about paid tiers.
4. You use an Apple Watch. Zero and Window both mention Watch features on their pages, and so does the independent timer above.
5. You hate accounts and ads. Check the privacy section for each app. Fastly needs no account, and the small independent app above says it has no ads.

A good test is to use the free version for a week. If you find yourself wanting something that sits behind the paywall, you've learned it's worth paying for. If you never touch it, you've saved money.

Before you start fasting

This is general information, not medical advice. Talk to a doctor before fasting if you have a medical condition (such as diabetes), take medication, are pregnant or breastfeeding, are under 18, or have ever had an eating disorder. Stop and get help if you feel unwell.

An app can't tell you whether a fasting plan is right for your body. It can only count the hours.

Questions

Which fasting app is best if I don't want to pay?

It depends on what you need. Window, BodyFast and Zero each offer a free timer, with different things behind their paid tiers according to their store pages. Fastly keeps the timer, presets, streak, weight and water logs free, and holds back the full history and CSV export for Pro. A small independent app that says it's free with no ads is another route. Compare the free list on each page against what you'd actually use.

Is there a better app than Zero?

Better depends on what you want from it. If Zero's nutrition tracking is more than you need, a timer-first app may feel lighter, and if you want custom fasting hours without a subscription, check which apps include them free. If you want more food tracking, Fastic is similar in scope. People ask this often (for instance in this thread), and the replies tend to split along those lines.

Are fasting apps with ads and subscriptions the norm?

Subscriptions are common among the big apps, and most of the ones we looked at offer a free version with a paid tier. Ads are harder to confirm from a store page, so read the privacy and age rating sections. A few smaller apps say they have neither.

Is there a fasting app with no account?

Yes. Fastly needs no sign-up and keeps your data on your phone. Some small independent timers do the same. Among the larger apps, Simple says you need an account, and several others list a user ID in their privacy section without saying whether you must sign in.

Which fasting apps have a widget?

According to their pages, Zero has a fasting widget, and Fastly has a home screen widget. The small independent app mentioned above lists widgets and Live Activities. Several others don't mention an iPhone widget on their pages, so check the app's current version.

Do I need an app, or is a timer enough?

A timer is enough for most people. A phone alarm set for when your window opens does the same job, and our schedule calculator and when can I eat timer work out the times for you. Add an app when you want history, streaks and reminders that you don't have to set up yourself.

Does using an app help me lose weight?

An app can make it easier to stay consistent, but it can't promise results. If the scale isn't moving, our guide on intermittent fasting and not losing weight lists what to check. If you work nights, see the night shift guide, and if you're thinking about a longer window, read OMAD, 20:4 or 18:6 first.

If you want to try a no-account timer, you can download Fastly free and use the free tools above in the meantime.