Period tracker with a passcode lock: what to look for

Short answer: yes, some period trackers can be locked. Dew locks with Face ID, Touch ID or your iPhone passcode for free. With Garden, Dew’s paid tier, you can add a 4-digit Dew passcode that your iPhone passcode can’t open, a decoy code that opens an empty-looking Dew, and a recovery key for the day you forget. Euki has a PIN and a decoy screen too. But a lock only guards the phone in someone’s hand. Where the app keeps your cycle matters just as much.

I build Dew, so read this with that in mind. I’ve kept to what I can check: how Dew’s lock works, because I wrote the rules, and what this site has already verified about other apps. Where I don’t know, I say so.

Why lock a period tracker app at all?

Most privacy writing about period apps is about companies: who stores your data, who it’s sold to, who can demand it. That matters, and I’ll come back to it. But for a lot of people the closer risk is a person, not a company.

• A shared phone or iPad. Families share devices. A tablet on the kitchen table is a diary anyone can open.
• A partner who knows your passcode. Many couples know each other’s iPhone codes. That’s fine for photos of the dog; less fine for notes about your body, your moods or your intimate life.
• Parents. A teenager’s phone is often a family phone in practice. A cycle log can say things she isn’t ready to say out loud.
• “Open it in front of me.” Sometimes it isn’t snooping, it’s pressure. Someone asks you to unlock the phone and show them. Some travellers are asked to unlock a phone at a border check, too.

A lock is the answer to that kind of moment. It is not the answer to a company holding your data on its server, or to a legal demand made of that company. That depends on where your cycle is stored, which I’ve written about in can police access your period tracker data? The two work together: keep the data off servers, and keep the app shut on the phone.

What to look for in a period tracker lock

“Has a passcode” is where the question starts, not where it ends. These are the things I’d check:

1. A code of its own. If your iPhone passcode opens the app, anyone who knows your iPhone passcode can open it. For a partner or a parent, that’s the whole problem.
2. Face ID that waits for you. Face ID is convenient. But if the app scans your face the instant it opens, someone can hold the phone up to you. Being able to choose to type a code instead matters.
3. A limit on guesses. A 4-digit code is only strong if nobody can try all of them. Waits after wrong tries should not be shortened by changing the phone’s date.
4. A way back that only you have. If you forget your code, the reset shouldn’t be something a person with your phone can do quietly in a minute.
5. It relocks, and hides from the app switcher. A lock that only asks on a cold start leaves the app open whenever you put the phone down.
6. Quiet notifications and widgets. “Your period is due tomorrow” on the Lock Screen undoes the lock.
7. A decoy, if your risk is pressure. A lock says “there’s something here.” A decoy shows nothing at all.

Period tracker apps with a passcode or PIN, compared

Here is what I can state with confidence. For apps where this site hasn’t verified the lock settings, I’ve written “not checked” rather than guess. Where the data lives comes from our earlier reviews.

Euki deserves real credit here. It was built for people whose risk is someone close, and its PIN and decoy screen say so. If you’re weighing it, read is Euki safe? For the storage column in more depth, the Period Tracker Privacy Index scores each app’s App Store privacy label.

How to hide a period tracker app on iPhone

“Hide” can mean three different things, and they solve different problems.

Hide the icon

Recent versions of iOS can lock or hide any app. Touch and hold the app’s icon, choose Require Face ID, then Hide and Require Face ID. The app leaves your Home Screen and goes into a locked Hidden folder at the bottom of the App Library. Euki takes another route and can disguise itself as a calculator.

Hide what’s inside

A hidden icon can still be found by someone who knows to look, and opening it in front of them shows everything. That’s what a decoy is for: the app is in plain sight, and it opens empty. More on Dew’s below.

Hide what the Lock Screen says

Notifications and widgets can say more than the app does. Turn on Dew’s discreet notifications and cycle details stay off the Lock Screen: reminders read “A gentle reminder” instead. Leave Dew’s widgets off your Lock Screen if anyone else sees your phone.

How Dew’s lock works

The free lock: Face ID, then your iPhone passcode

Turn on App Lock in Dew (it’s under Make it yours › Dew › Lock, and searching for “lock” or “Face ID” finds it). From then on, Dew asks for Face ID or Touch ID each time it opens, falling back to your iPhone passcode. Under Ask again after you choose how soon it locks once you leave: immediately, after 1 minute, or after 5 minutes. When Dew relocks it closes anything that was open, and when you leave the app a privacy cover hides it in the app switcher.

This lock is free for everyone, no Garden needed. It has one honest limit: anyone who knows your iPhone passcode can get past it. If that’s your situation, read on.

With Garden: a passcode that’s yours alone

With Garden you can set a 4-digit Dew passcode. Once it’s set, your iPhone passcode never opens Dew. Only your Dew passcode does, or Face ID if you allow it. There’s a switch, Face ID opens Dew: leave it on for convenience, or turn it off so only your passcode opens Dew.

Two smaller details matter more than they look. With a Dew passcode, the lock screen shows a keypad and doesn’t scan your face by itself; Face ID is a button you choose to press. So if someone holds the phone up to you, you can type a code instead. And if a new face is added to the iPhone, it opens nothing until you type your Dew passcode once. Dew’s words for it: “Face ID changed on this iPhone. Enter your passcode once to use it here again.”

Five tries, then a wait

You get five free tries. After that Dew waits 1 minute, then 5 minutes, then 15 minutes for each further wrong try. The count survives closing the app, and it’s timed on the phone’s own uptime as well as the clock, so moving the date forward doesn’t shorten a wait. Face ID, if you allow it, still works during a wait.

If you forget your passcode

This is where most locks either strand you or let anyone in. Dew has three ways back, and all three need something only you have:

• Face ID. If Face ID opens Dew, use it to choose a new passcode.
• A recovery key (since 1.4.1, with Garden). An optional phrase you choose, at least 8 characters, not a pattern and not your passcode. Capitals and spaces don’t matter. Dew keeps only a scrambled copy on this iPhone and can never show it to you again, so keep it somewhere that’s yours. The right key lets you choose a new passcode at once; wrong keys count toward the same tries and waits.
• Your iPhone passcode, plus 24 hours. It can’t open Dew, but it can start a 24-hour wait, after which you choose a new passcode. Until then, every time Dew is really unlocked it first says “A passcode reset was started on …” with a button to cancel it. So someone who knows your iPhone passcode can’t quietly take over.

The decoy passcode

Also with Garden, you can set a decoy passcode: in Dew’s words, “a second code that opens Dew looking brand new: empty, as if it’s never been used. For moments someone asks you to open the app.”

It’s built so it can’t give you away. The decoy unlocks with the same animation and haptic as your real code. While it’s open, Dew doesn’t read or change your real days at all: anything typed there is thrown away when Dew locks again. Dew’s widgets are cleared, a period Live Activity ends, and Dew’s notifications are removed, so a reminder can’t reveal your real dates. Your evenings, your settings and your recovery key are out of reach from the decoy.

The setup screen also says what it can’t do, and so will I: a widget might show for a moment before it refreshes, and Dew can’t hide what other apps on your phone show. If you’ve connected Dew to Apple Health, for example, your period days are there too, behind Apple’s lock, not Dew’s. Changing your real passcode clears the decoy, so you’d set it up again.

Where the codes are kept

Your passcode is never stored as digits. Dew keeps only a salted, scrambled hash in the iPhone’s Keychain, on this device only, never synced to iCloud and never logged. Delete All removes it. If Garden ends, you’re never locked out: Face ID or your iPhone passcode opens Dew for now, and your own passcode comes back exactly as it was when Garden does.

What a lock can’t do

A lock is built for coercion and for a hand on your phone. It isn’t a defence against forensic tools that copy a whole phone, and it does nothing for data an app has already sent to a server. That’s why the lock is the second half of Dew’s privacy, not the first.

The first half is that there’s no Dew account and no Dew server. Your cycle lives on your iPhone and, if you turn on sync, in your own end-to-end encrypted iCloud, which neither Apple nor I can read. Here’s how that works. There’s no email to tie it to you either; see period trackers that work without an account.

The short version

• You want the app closed to anyone without your face: Dew’s free lock, or iOS’s own Require Face ID.
• Someone close knows your iPhone passcode: a code of the app’s own. In Dew, that’s the Dew passcode with Garden.
• You might be asked to open it in front of someone: a decoy. Dew and Euki both have one.
• You don’t want a company holding your cycle at all: pick an app that keeps it on your phone, and then lock it. More in what makes a period tracker private.