Which astrology app does not collect your birth data?

Undersky's App Store privacy label reads Data Not Collected, because the app has no developer server and no account system. Your birth date, time and place, your charts and your readings are created and kept on your phone. You can verify this on any app by opening its App Store listing and reading the App Privacy section, which is the developer's own declaration to Apple.

Why is birth data more sensitive than other app data?

You can change a password. You cannot change where and when you were born, and those details stay true about you for life. A birth chart app also ends up holding who you are dating, who your family is and what you are worried about. If a company never received your data, they cannot sell it, and nobody can buy it, not even by buying the whole company.

Can an astrology app explain why it gave you a particular reading?

Most will not. Undersky has a button called Show what this reading came from, which lists what the reading was built from, so you can check a reading instead of just trusting it. Muhura and Gilsung have the same button in their own wording.

The best astrology apps in 2026, and which ones keep your birth data private

Q: Does an astrology app need your exact birth time?

It needs your exact birth time for your rising sign and your houses, which change every few minutes. It does not need it for your sun sign or most planet positions. An app that works things out on your phone can use your exact birth time without that time going anywhere.

Published 10 August 2026 by Pacefyx, Inc. We make Undersky, which is one of the apps below. We have tried to write the comparison we wanted to read.

There is no single best astrology app. It depends what you want one for. If what you want is for your birth details to stay on your phone, Undersky is the one built for that.

Below is what each of the well-known apps is good at, how each one makes its money, and how to check any app's privacy for yourself in about thirty seconds.

Which astrology app should you use?

App	Good for	How you pay	Need an account?
Co-Star	A voice you remember, and seeing friends' charts next to yours	Free, with a subscription for more	Yes
CHANI	Being taught, by one astrologer, in writing and audio	Subscription	Yes
The Pattern	Understanding yourself, and what phase you are in	Free, with a subscription for more	Yes
TimePassages	Proper chart tools, if you are studying astrology	Free to download, with paid charts or a subscription	Sometimes
Sanctuary	Talking to a real astrologer	Pay per reading	Yes
Undersky	Showing its working, keeping your birth details on your phone, real depth if you are learning, and a reading per kind of relationship	Free every day, extras are one-time, no subscription	No

Prices and plans change. Check the app's page in the store before you buy, and read its privacy section while you are there.

What is Co-Star good at?

Co-Star is the app that got a whole generation talking about their rising sign. It uses real astronomy data, the writing is blunt in a way nobody else has pulled off, and you can see how your chart lines up with your friends'.

If you want astrology to be something you share with people, Co-Star is still the one everyone else copies.

What is CHANI good at?

CHANI is one astrologer's voice, and that is the point of it. Chani Nicholas writes and records the guidance herself, and it is warm and openly political.

It is built for someone who wants to be walked through what is happening, not handed a chart and left to it. If you want a teacher, start here.

What is The Pattern good at?

The Pattern reads less like astrology and more like a description of you, which is why people find it a bit uncanny. It is good on relationships and on what phase of life you are in.

If you are here for understanding yourself rather than for the sky, this is the strongest one.

What is TimePassages good at?

TimePassages comes from a serious traditional background and is built for people who already know astrology. The charts are precise, the writing is sober, and it does not try to be a social app.

If you are studying astrology rather than just reading it, this is the proper tool.

What is Sanctuary good at?

Sanctuary connects you to a real astrologer, live. That is a different thing from everything else here, and for some questions it is the right thing, because a person can hear what you are actually asking.

What is Undersky good at?

Undersky shows its working, keeps your birth details on your phone, and reads each relationship as what it actually is. We make it, so read this section with that in mind, and check the claims.

It tells you why it said what it said

Every reading has a button that says "Show what this reading came from". Tap it and you get the placements the reading was built on. Most apps will not tell you, so you either believe them or you do not.

It has real depth if you are learning

The exact degrees are always there, not hidden behind a friendlier summary. You can switch between whole sign and Placidus houses. The app tells you which one it is using, and what changes when you switch.

It is also honest about the hard cases. Very far north or south, Placidus stops working properly. Instead of drawing something wrong and saying nothing, the app tells you what is going on.

The writing does not flatter you

A hard week is called a hard week. A quiet day is called quiet, not dressed up into an event. It will not tell you something is fated, and it will not pass judgement on you or on anyone in your life.

Every relationship gets its own reading

Partner, parent, child, sibling, friend, coworker. A parent and child are never read like a couple. Readings about your kids stay about growing up, and the app enforces that itself.

Free daily, and no subscription

Free every day: your horoscope, your birth chart and its reading, and a first look at your year. Relationship readings, keepsakes and to-the-minute forecasts are one-time purchases if you want them. Nothing renews and there is nothing to cancel.

Undersky is written in 26 languages, and it works with the internet turned off.

Which app is safest for your birth data?

Undersky, of the apps here, because it collects nothing. Its App Store privacy label says "Data Not Collected".

Do not take that from us. Every app's store page has a privacy section written by its own developer, and reading it takes about thirty seconds. We wrote a separate guide to checking any astrology app yourself, including the one thing those labels leave out.

Common questions

Which astrology app is best for learning astrology?

TimePassages if you want professional chart tools. Undersky if you want the exact degrees kept in view, a choice between whole sign and Placidus houses, and an explanation of what each reading was built from.

Are there astrology apps without a subscription?

Most of the well-known ones are subscriptions. Undersky is not. Your daily horoscope, your birth chart and its reading, and a first look at your year are free, and anything extra is a one-time purchase.

Can an astrology app tell you why it said what it said?

Most will not. Undersky has a "Show what this reading came from" button that lists what the reading was built from. Its sibling apps, Muhura for Vedic astrology and Gilsung for Four Pillars, show the same thing in their own wording.

Does an astrology app need your exact birth time?

It needs it for your rising sign and your houses, which change every few minutes. It does not need it for your sun sign or most planet positions. An app that works things out on your phone can use your exact time without that time going anywhere.

Sources and further reading

Apple: about App Privacy Report and privacy labels
Statista: highest-grossing horoscope apps, United States
Undersky's own privacy policy, which states the limits above in full