Best Free Stargazing Apps

Your smartphone can be a surprisingly useful tool under the night sky. With the right app, you can identify stars, planets and constellations simply by pointing your phone upward, discover what’s visible tonight, track the International Space Station or check whether the weather is likely to cooperate before heading outside.

There are plenty of astronomy apps available, but many advertised as free provide little more than a short trial before requiring payment. For this guide, we’ve taken a stricter approach: at the time of writing, every app listed below can be used for stargazing without paying. Some offer optional purchases or subscriptions that unlock additional features, but payment isn’t currently required to use the core free app.

We’ve included apps for both iPhone and Android, ranging from full interactive planetariums to simpler star finders and specialist tools for telescope users, satellite tracking and observing conditions. Whether you’re completely new to stargazing or already spend plenty of nights outside looking upward, there should be something here worth adding to your phone.

If you’re looking for more advanced paid features, see our guide to the best premium stargazing apps. We also have a separate guide to desktop astronomy and stargazing software.

Best Free Stargazing Apps at a Glance

Stellarium Mobile — Best Free All-Round Stargazing App

Stellarium Mobile turns your phone into a pocket planetarium, showing an accurate view of the night sky for your location and time. You can identify stars, planets and constellations, or search for an object and see where to find it.

The free version includes a large catalog of stars and deep-sky objects, constellation illustrations and information about planets, comets, asteroids and satellites. You can also explore how the sky looks at different times and dates. A red night mode helps preserve your dark adaptation while using the app outside.

Stellarium is a particularly good starting point if you only want to install one astronomy app. The core features can be used without paying, while optional upgrades add larger catalogs and more advanced observing features.

Available for: iOS | Android
Cost: Free, with optional paid upgrades

Sky Tonight — Best for Seeing What’s in the Sky Tonight

Sky Tonight combines an interactive sky map with tools designed to answer a particularly useful question: what can I see tonight? It can identify objects in the sky, while its search and calendar features help you find astronomical events worth looking for.

The app shows when objects rise, reach their highest point and set, along with information about their visibility from your location. It also highlights upcoming events such as conjunctions, meteor showers and opportunities to see the planets, making it useful for planning an observing session rather than simply identifying what you’re already looking at.

The free version provides access to the app’s sky objects and astronomical events and can be used continuously without paying. Optional Premium features remove advertising and some interface restrictions.

Available for: iOS | Android
Cost: Free, with optional paid upgrades

Star Walk 2 Plus — Best for Beginners

Star Walk 2 Plus is designed to make exploring the night sky easy, even if you don’t yet know many stars or constellations. Its interactive map follows the direction you’re looking, allowing you to explore celestial objects without first learning how to navigate a traditional star chart.

Its colorful graphics and straightforward controls make it particularly approachable for beginners. You can tap objects to learn more about them, search for something you want to find and move through time to see how the sky changes during the night. The app also includes information about upcoming astronomical events.

The free version can be used continuously without paying, although it includes advertising and offers optional purchases or subscriptions for additional content and features. If you’re completely new to stargazing and want something visually engaging without a steep learning curve, Star Walk 2 Plus is a good place to begin.

Available for: iOS | Android
Cost: Free, with optional paid upgrades

Star Chart — Best Completely Free Stargazing App

Star Chart offers a straightforward way to explore the night sky without overwhelming you with advanced observing tools. Hold your phone toward the sky and the app shows the stars, planets and other objects in that direction, making it easy to put a name to something that has caught your eye.

You can move around its 3D representation of the sky, search for celestial objects and explore how the sky appears from different locations. It also lets you shift backward or forward in time to see how the positions of objects change.

Its simplicity is the main attraction, and the current app provides its features without requiring a subscription. If you want an accessible general-purpose star chart without immediately moving into specialist observing tools, it’s a particularly attractive free option.

Available for: iOS | Android
Cost: Free

SkyView Lite — Best for Pointing Your Phone at the Sky

SkyView Lite makes identifying objects particularly intuitive: point your phone toward the sky and the app overlays the names and positions of stars, planets, constellations and satellites onto the view from your camera.

The augmented-reality approach makes it useful when you’ve spotted a bright object and simply want to know what you’re looking at. You can also search for particular objects and follow on-screen guidance to locate them, while a time-control feature lets you explore how the sky changes through the night.

The Lite version can be used without paying and provides the core sky-identification experience. Additional content and features are available through the paid version and optional purchases, but they aren’t necessary for basic stargazing.

Available for: iOS | Android
Cost: Free, with optional paid upgrades

Sky Map — Best Completely Free Android Stargazing App

Sky Map is one of the simplest ways for Android users to identify objects in the night sky. The map moves with your phone, showing the stars, planets, constellations and nebulae in that part of the sky. You can also search for an object and follow the on-screen guidance to find it.

Originally developed as Google Sky Map, the project is now independently maintained and open source. It continues to receive updates, so this isn’t simply an old astronomy app surviving in an app store.

Sky Map is completely free and open source, making it an excellent choice for Android users who simply want a straightforward sky map without subscriptions or locked premium features.

Available for: Android
Cost: Free

SkEye — Best for Using With a Telescope

SkEye combines a conventional planetarium with a more unusual feature for telescope owners. As well as identifying stars, planets and constellations, it includes a PUSHTO mode designed to help guide a manually operated telescope toward objects in the sky.

The free app includes Messier objects, a selection of brighter NGC objects, planets, meteor showers and comets, along with night mode, coordinates and search guidance. The interface and telescope features make SkEye somewhat more specialized than the beginner-oriented apps above, but that’s precisely why it earns a place here.

You don’t need a telescope to use SkEye, but there are simpler choices if you only want to identify constellations with your phone. Its real appeal is for Android users who are beginning to combine smartphone astronomy with observing through a telescope.

Available for: Android
Cost: Free, with optional paid features

ISS Detector — Best for Tracking the ISS and Satellites

The International Space Station can become one of the easiest artificial objects to spot once you know when and where to look. ISS Detector calculates visible passes for your location and can alert you shortly before the station is due overhead, while also showing where in the sky to look.

The free app provides the core ISS-tracking functionality and also takes observing conditions into account. Optional premium features expand the app to cover additional spacecraft and satellites, including Starlink trains and amateur-radio satellites.

ISS Detector therefore isn’t a replacement for a general star-map app such as Stellarium. It’s a useful specialist addition if seeing the ISS is part of your interest in the night sky.

Available for: iOS | Android
Cost: Free, with optional paid upgrades

Clear Outside — Best for Stargazing Weather

Even the best star map isn’t much help when the sky is covered in cloud. Clear Outside approaches stargazing from a different direction by providing weather forecasts specifically designed for astronomers, with particular emphasis on cloud cover.

Its seven-day hourly forecasts break cloud into low, medium and high layers and include rain, wind, temperature, dew point and other weather information. The app also provides Moon and Sun rise and set times, periods of astronomical darkness and ISS pass information.

That makes Clear Outside particularly useful once you begin planning observing sessions rather than simply stepping outside and hoping for clear skies. It isn’t a sky-identification app, but it answers an equally important stargazing question: is tonight actually worth going outside?

Available for: iOS | Android
Cost: Free

Which Free Stargazing App Should You Choose?

If you’re only going to install one app, Stellarium Mobile is a good place to start. It combines an easy-to-use sky map with enough depth to remain useful as you become more familiar with the night sky.

But no single app does everything. Sky Tonight is particularly useful for planning what to observe, SkEye adds practical tools for telescope users, ISS Detector makes satellite spotting much easier, and Clear Outside can help you decide whether it’s worth heading outside in the first place.

The best approach is often to start with a general sky map and add one or two specialist apps as your interests develop. A smartphone won’t replace learning your way around the night sky, but used well, it can make that learning considerably easier.