Astronomy software spans three jobs that buyers often mix up: viewing and charting the sky, controlling a telescope and camera through the night, and processing the frames afterwards.
This guide ranks tools by first-weeks effort, the full bill, vendor independence and who each product serves. Donation projects, perpetual licences and subscriptions all appear here, so costs are compared over years.
Vendors can pay for more visibility on this website, for example a higher place in a ranking or more room on a page. Commercial relationships can also affect which products we feature and how prominently. Every vendor link is marked the same, whatever the arrangement behind it. How that works.
In short
What astronomy software does
Astronomy software simulates the night sky, plans observing sessions, drives telescopes and cameras, or calibrates and stacks the resulting images, running on desktops, phones or small observatory controllers.
In this order: setup effort, what it really costs, how your data comes back out, whether you can leave, and who each astronomy tool is built for. A separate rule reserves the first three places for challengers and moves the household names to place 4 and below. The reasoning behind the five tests, and behind having no score out of ten, is set out on the how we work page.
Planetarium for your computer, funded by donations and licensed GPL-2.0
Ranked #1 of 14 in Best Astronomy Software in 2026.
Free tierOpen sourcePublished pricingElsewhere
Stellarium opens the list because a newcomer can install it without a licence key, a trial clock or a card. The project is funded by donations, the repository declares GPL-2.0, and Linux, macOS and Windows builds exist, including Windows on ARM.
The cost is hardware: the minimum is 1 GiB of RAM with OpenGL 2.1, and the recommended level is 4 GiB with OpenGL 3.3. It shows the sky and describes no telescope control.
What stands out
GPL-2.0 licence
Desktop planetarium
Donation funded
Where it costs you
The page read lists a planetarium and no equipment control, so imaging sessions need a second program.
The recommended specification is 4 GiB of RAM and OpenGL 3.3, which is above the stated minimum for older laptops.
Right for
Anyone wanting a no-cost sky simulator on Windows, macOS or Linux.
Wrong for
Observatory owners who need automated overnight capture sequences.
Not stated by the vendorFree of charge, no paid plans listed; donations via Open Collective
Equipment control and sequencing for night imaging, supported by donations
Ranked #2 of 14 in Best Astronomy Software in 2026.
Published pricingElsewhere
N.I.N.A. suits an imaging rig where one program must talk to the camera, mount, focuser, filter wheel and dome. Its Advanced Sequencer supports loops, event-triggered actions and reusable templates, and plugins extend it.
Money is not the barrier, because the project asks for donations and sponsors. The barrier is a single named maintainer, Stefan Berg, and a site that states no licence and no platforms, so continuity and compatibility are things to check yourself.
What stands out
Advanced Sequencer
Plate solving framing
Plugin framework
Where it costs you
The site names no licence, so reuse rights are unclear from the page alone.
Supported operating systems are not stated on the page read.
Right for
Imagers who want sequencing, framing and focus automation without a licence fee.
Wrong for
Visual observers who only want a star chart.
Not stated by the vendorDescribed as fully free; supported by donations and sponsors
Observatory automation sold as a perpetual licence by an Italian seller
Ranked #3 of 14 in Best Astronomy Software in 2026.
Published pricingEurope
Voyager attaches a fixed price to observatory automation: the BASE licence covers one user on three PCs you own, the licence file arrives within 24 hours of payment, and the 45-day trial lets you test before paying.
Renewal after the first year is priced separately, and the array tiers step up by node count. The seller is a named Italian business rather than a platform, which makes it easy to know who answers. Larger observatories land in quote territory.
What stands out
Perpetual licence
Three PCs per licence
Array licences
Where it costs you
Updates and support last one year, after which a renewal is needed to continue receiving them.
Some array purchase buttons are marked coming, so multi-node buyers cannot always order online.
Right for
Single-site imagers who prefer owning a licence over a monthly subscription.
Wrong for
Buyers who only want a free sky chart.
ItalyPublished perpetual licence prices in euros; 45-day trial; yearly renewal for updates
Desktop planetarium from KDE for Windows, macOS and Linux
Ranked #4 of 14 in Best Astronomy Software in 2026.
Published pricingElsewhere
KStars is run under the KDE name, which is a trademark of KDE e.V., so it has an institution behind it that smaller projects lack. Its sky model scales to 100 million stars alongside a deep-sky catalogue, and the download page covers three desktop systems.
The weak points are on the page itself: no licence is stated, no price is shown beyond the word free, and the description stops at simulation, leaving equipment control to others.
What stands out
KDE project
100 million stars
Cross-platform desktop
Where it costs you
The licence is not stated on the page read, which leaves reuse terms unconfirmed.
Only the simulator is described, so imaging automation has to come from another program.
Right for
Desktop users who want a large star catalogue on any of three systems.
Wrong for
Imagers who need ready-made capture sequences and automation.
Not stated by the vendorDescribed as free software; no price listed
Image calibration, stacking and enhancement, including SER video for lucky imaging
Ranked #5 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
Siril sits after the telescope: it takes captured frames, calibrates and stacks them, and covers enhancement and science tasks. SER video support serves lucky imaging of planets.
Release cadence looks active, with 1.4.5 dated 28 October 2026, and each major desktop system has a build, though the Linux Flatpak is third party. A buyer should note that the licence is not stated and that the wording on the page never settles the price question.
What stands out
Image stacking
SER video
Apple Silicon build
Where it costs you
The site takes donations through PayPal, Liberapay and Dogecoin yet states no price or licence.
It handles processing only, so capture and planning need other programs.
Right for
Imagers who already have frames and need stacking on Linux, Windows or macOS.
Wrong for
People who need to control a telescope or camera.
Not stated by the vendorDonation funded; price not stated on the page read
Windows imaging capture tool from Sofia with a time-unlimited demo
Ranked #6 of 14 in Best Astronomy Software in 2026.
Pricing on requestEurope
Astro Photography Tool lets you evaluate its capture features for as long as you like, because the demo carries no time limit, and a purchase page unlocks the extra features of the full version.
The page gives Sofia, Bulgaria as its location and shows a current release dated 4 June 2026. The price is not visible, and the product runs on Windows 7, 8, 8.1, 10 and 11 only, so check your hardware first.
What stands out
Windows only
Unlimited demo
Sofia, Bulgaria
Where it costs you
Windows is the only listed platform, so a Raspberry Pi or Mac observatory computer cannot use it.
The price of the full version is not visible on the page read.
Right for
Windows imagers who want to test thoroughly before buying anything.
Wrong for
Mac or Linux users building a remote observatory.
BulgariaTime-unlimited demo; full version sold, prices not shown
Sky charting from 16 catalogues under the GNU General Public License
Ranked #7 of 14 in Best Astronomy Software in 2026.
Free tierPublished pricingElsewhere
Cartes du Ciel is for the person who wants to decide how a chart looks. Sixteen catalogues, adjustable star and nebula size and colour, coordinate grids, picture overlays and visibility conditions all sit in the settings.
The GNU General Public License covers it, and downloads exist for three systems. The cost of that depth is a page with no owner and no country, and an older Windows-only version that is no longer maintained.
What stands out
16 catalogues
GNU GPL
Chart display options
Where it costs you
The page names no company or country, so accountability is hard to establish.
The older Windows-only 2.76 release is no longer maintained.
Right for
Chart makers who want deep control over catalogues, colours and labels.
Wrong for
Phone users looking for a point-and-view sky guide.
Not stated by the vendorFree download; no price shown
Sky guide for iOS and Android sold as Basic, Plus and Pro
Ranked #8 of 14 in Best Astronomy Software in 2026.
Published pricingElsewhere
SkySafari is the mobile option in this list. Three editions, Basic, Plus and Pro, carry published prices, and the page shows a sale price next to a regular one, so the amount you pay depends on timing.
Premium is a membership you may add inside the app, and a trial is offered. Only iOS and Android downloads are listed, and no country is given, so it works for field use but not for a desktop observatory.
What stands out
iOS and Android
Three editions
Premium membership
Where it costs you
Download links cover iOS and Android only, so there is no listed desktop version.
The Premium membership price is not shown, so the full cost depends on opting in.
Right for
Observers who carry a phone or tablet to the eyepiece.
Wrong for
Desktop users who need Windows or Linux software.
Not stated by the vendorPublished prices per edition; optional Premium membership with a trial
Observatory controller hardware and software built around the INDI protocol
Ranked #9 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
StellarMate mixes software and hardware: an operating system for Raspberry Pi or a mini PC, plus Controller and Pro devices. Equipment of many kinds works through the INDI protocol, including mounts, cameras, filter wheels, focusers, domes, rotators and weather stations.
HotSpot mode serves remote sites with no network, and tablets show live stacking. Prices are absent from the page read and one model is pre-order only, so costing the setup takes a direct enquiry.
What stands out
INDI protocol
HotSpot mode
Ekos suite
Where it costs you
The products are listed without prices, so the hardware budget is unknown until you ask.
The Pro X is on pre-order, so it cannot be bought for delivery now.
Right for
Imagers who want a small field computer running mounts, cameras and focusers.
Wrong for
Buyers who want only software for an existing PC.
Not stated by the vendorPrices not shown on the page read; trial not mentioned
Automated night-sky imaging sequences sold as a subscription
Ranked #10 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
Sequence Generator Pro targets automated imaging runs, with a gear compatibility page to check cameras, filter wheels and mounts before buying. The Lite versus Pro comparison implies tiers, but the page names no plans or prices.
Licences are handled in a Manage Licenses area, and the company appears as Main Sequence Software through its forum address. Without a trial or visible price, the sensible step is to confirm cost and compatibility in writing first.
What stands out
Subscription
Lite and Pro
Gear compatibility page
Where it costs you
Purchase leads to a subscription, so the cost recurs for as long as you use it.
No trial is mentioned and no price is shown, which makes testing and budgeting harder.
Right for
Imagers who want automated sequences and accept a recurring subscription bill.
Wrong for
Buyers who prefer to own a licence outright.
Not stated by the vendorSubscription; plan names and prices not shown on the page
Observation planner for macOS and Windows with a try-first download
Ranked #11 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
AstroPlanner covers planning rather than viewing, and its shareware model means the working program can be tried before money changes hands. Current builds need macOS 10.14 or Windows 8.1, while an older version serves ageing machines.
The copyright holder is iLanga, Inc., with a range of years from 2011 to 2026. Prices stay hidden until you reach the purchase page, so ask about editions before committing.
What stands out
Shareware
macOS and Windows
Observation planning
Where it costs you
Editions and prices are not shown on the page read, so budgeting means visiting the purchase page.
No country is stated for iLanga, Inc.
Right for
Observers on Mac or Windows who plan sessions and want to test first.
Wrong for
Anyone who needs a live sky simulator or camera control.
Not stated by the vendorShareware; fully functional download to try, prices not shown
Observation planning and logging for Windows, with a trial edition
Ranked #12 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
Deep-Sky Planner 9 is described as observation planning and logging software for astronomers, which places it beside AstroPlanner and ahead of the planetariums for people who keep records.
A trial edition is a digital download, so testing is possible, but the buy button leads to a placeholder and the price is unknown. Its edition names, Deep-Sky Planner for Windows and Windows Edition, show a single platform. Copyright mentions Knightware, LLC and Phyllis K. Lang.
What stands out
Windows only
Trial edition
Observation logging
Where it costs you
Only a Windows edition is named on the page read.
The buy button links to a placeholder and shows no price.
Right for
Windows observers who want to log and plan deep-sky sessions.
Wrong for
Mac users or anyone wanting an interactive planetarium.
Not stated by the vendorTrial edition download; buy button shows no price
Four paid Starry Night 8 editions for Windows and Macintosh
Ranked #13 of 14 in Best Astronomy Software in 2026.
Published pricingElsewhere
Starry Night is the priciest planetarium here, which is why it sits low: the Pro Plus 8 edition lists at USD 259.95 against nothing to pay for Stellarium or KStars.
The four-step edition ladder at least makes the cost clear, running through CSAP 8, Enthusiast 8, Pro 8 and Pro Plus 8. Windows and Macintosh are covered, but no trial is mentioned, and a 2021 copyright line leaves doubt about how current the page is.
What stands out
Four editions
Windows and Macintosh
Simulation Curriculum
Where it costs you
The Enthusiast 8 price appears without a currency, so the real amount is ambiguous.
The footer shows 2021, so the page may lag the product.
Right for
Buyers who want a boxed-style desktop planetarium priced by edition.
Wrong for
Anyone who needs to try the product before paying.
Not stated by the vendorPublished edition prices from entry level to Pro Plus; trial not mentioned
Software Bisque's TheSky in Serious and Professional editions
Ranked #14 of 14 in Best Astronomy Software in 2026.
Pricing on requestElsewhere
Software Bisque, Inc. names two editions of its planetarium and bundles imaging software for the operating system you choose. The forums include a TheSky Linux section, which hints at wider platform use, though the platform detail is not specified.
The page read shows neither prices nor a trial, and licensing sits behind a Software License page. That vagueness and the lack of a stated country put it last.
What stands out
Serious and Professional
Imaging bundle
Linux forum
Where it costs you
No price, currency or trial appears, so the cost cannot be judged from the page read.
The licensing model is only linked as an EULA and not explained.
Right for
Buyers already invested in the Software Bisque product family and its forums.
Wrong for
Shoppers who want to compare prices before contacting anyone.
Not stated by the vendorNo prices listed; no trial mentioned
Astronomy software simulates the night sky, plans observing sessions, drives telescopes and cameras, or calibrates and stacks the resulting images, running on desktops, phones or small observatory controllers. Differences that change the outcome seldom sit in the features. Here is the sequence we would follow.
01
Work out how much a sales call is worth to you
Only 7 of the 14 print a price; 7 quote per organisation. Comparable without a sales call: Stellarium, N.I.N.A., Voyager, KStars, Cartes du Ciel, SkySafari, Starry Night.
02
Decide how much the jurisdiction matters
These 14 vendors are established in 3 countries across 2 regions (Elsewhere 12, Europe 2). That decides whose disclosure law applies to what the vendor holds, wherever the servers are.
03
Check the open source options
Source code is available for Stellarium. Running it yourself swaps the licence fee for your own upkeep.
Astronomy software splits into sky viewers, capture controllers and image processors
A search for astronomy software returns products that never compete with each other. Stellarium, KStars, Cartes du Ciel and Starry Night simulate the sky for viewing and charting. N.I.N.A., Voyager, Astro Photography Tool, Sequence Generator Pro and StellarMate talk to cameras, mounts, focusers and filter wheels during an imaging night.
Siril works after the night, calibrating and stacking the frames that those controllers captured. AstroPlanner and Deep-Sky Planner sit in a fourth group that plans and logs sessions. Buying one tool from the wrong group leaves the real job undone. Write down which of the four jobs you need this season, then restrict the shortlist to that group before comparing prices, licences or platforms.
Name the job: view, plan, capture or process
Match each candidate's own description to that job
Expect to combine two tools, such as N.I.N.A. and Siril
Price models run from donations to perpetual licences and subscriptions
The money side of this market has no common meter. Stellarium is funded by donations and lists no paid plans, Cartes du Ciel is a free download, and Siril and N.I.N.A. ask for donations. Voyager sells a perpetual licence with one year of updates and a yearly renewal, Sequence Generator Pro leads to a subscription, and Starry Night prices four editions between roughly USD 60 and USD 260.
SkySafari charges per edition and adds an optional Premium membership. Several vendors show no price at all, including StellarMate and TheSkyX. Work out what you pay in year one and in year three, including renewals, and ask any vendor with a hidden price to confirm the figure in writing.
Compare year-one and year-three cost, not the headline
Ask whether updates stop when a renewal lapses
Request written prices where the page shows none
Operating system and observatory computer decide more than features
Platform support removes products faster than any feature list does. Astro Photography Tool and Deep-Sky Planner name Windows only, AstroPlanner covers macOS and Windows, and SkySafari offers iOS and Android downloads. Siril publishes builds for Linux, Windows and both Mac chip types, while Stellarium and KStars cover all three desktop systems.
StellarMate runs on a Raspberry Pi or mini PC, which suits an observatory with no Windows machine. Age matters too: Cartes du Ciel version 3 has limits on Windows 95, 98 and Me, and AstroPlanner keeps older builds for macOS 10.11. List the computer that will sit at the telescope before reading any comparison, because a missing driver or operating system cannot be fixed by a later purchase.
Identify the operating system at the telescope
Check the minimum version in each vendor's own list
Confirm the camera and mount are on the compatibility page
Unclear owners and countries are common among astronomy software vendors
Many astronomy projects publish little about who stands behind them. Stellarium names a project coordinator but no organisation, Cartes du Ciel names no company, and N.I.N.A. is maintained by one named person. Voyager, by contrast, names a seller and a town in Italy, and Astro Photography Tool names Sofia, Bulgaria.
TheSkyX and Starry Night give a company name but no country. None of this is a fault, since donation projects often run without a legal entity on show. It does change your risk: with a single maintainer or no stated owner, keep exported sequences, profiles and installers, and plan ahead for the day a project slows down or changes hands, so that your nights are not stranded.
Note who is named as owner or maintainer
Keep a local copy of the installer and settings
Prefer a stated licence if you plan to rely on the tool for years
What goes wrong most often when buying astronomy software
Choosing a planetarium such as Stellarium when the real need is a capture controller such as N.I.N.A. or Voyager.
Paying for Starry Night or SkySafari before trying the free options, then finding the catalogue depth is not needed.
Assuming a Windows-only tool such as Astro Photography Tool will run on the Raspberry Pi or Mac at the telescope.
Treating a missing price, as on the TheSkyX or StellarMate pages, as if it meant low cost instead of asking.
07
Frequently asked questions
7 answers
What is the best astronomy software in 2026?
Stellarium leads our ranking of 14. Stellarium describes itself as a free open source planetarium, and its repository declares GPL-2.0, so you pay nothing and can inspect the code.
Builds cover Linux, macOS and Windows including ARM64, and a browser version is linked. The page describes a sky viewer and lists no camera or mount control. Only a project coordinator is named, so the organisation and its country stay unknown.
Which astronomy tools publish their pricing?
7 of the 14, with the pricing model each one publishes:
Stellarium: Free of charge, no paid plans listed; donations via Open Collective.
N.I.N.A.: Described as fully free; supported by donations and sponsors.
Voyager: Published perpetual licence prices in euros; 45-day trial; yearly renewal for updates.
KStars: Described as free software; no price listed.
Cartes du Ciel: Free download; no price shown.
SkySafari: Published prices per edition; optional Premium membership with a trial.
Starry Night: Published edition prices from entry level to Pro Plus; trial not mentioned.
7 vendors do not print a price.
Is there a free astronomy tool?
Stellarium, Cartes du Ciel come with a no-cost entry point, a free plan or a self-hosted edition.
Where are these astronomy software vendors established?
Vendor countries on this page, Elsewhere 12, Europe 2:
Stellarium: Not stated by the vendor.
N.I.N.A.: Not stated by the vendor.
Voyager: Italy.
KStars: Not stated by the vendor.
Siril: Not stated by the vendor.
Astro Photography Tool: Bulgaria.
Cartes du Ciel: Not stated by the vendor.
SkySafari: Not stated by the vendor.
StellarMate: Not stated by the vendor.
Sequence Generator Pro: Not stated by the vendor.
AstroPlanner: Not stated by the vendor.
Deep-Sky Planner: Not stated by the vendor.
Starry Night: Not stated by the vendor.
TheSkyX: Not stated by the vendor.
Which astronomy tools are open source?
Stellarium.
What should you use instead of Stellarium?
N.I.N.A. and Voyager are the next two on this page. N.I.N.A. is for Imagers who want sequencing, framing and focus automation without a licence fee.; Voyager is for Single-site imagers who prefer owning a licence over a monthly subscription..
Who should not buy Stellarium?
Observatory owners who need automated overnight capture sequences.. The page read lists a planetarium and no equipment control, so imaging sessions need a second program..
Vendors who think their astronomy software product should be here can tell us about it: what it does, who it is for. The call is ours, and software advice sets out what being listed means.
