Astrophotography Software for Mac: What Runs, and What Doesn't

If you have just started astrophotography on a Mac you have probably already hit this: nearly every tutorial you find tells you to download DeepSkyStacker, and DeepSkyStacker does not run on macOS. Neither does AutoStakkert!. Neither does RegiStax. Neither does Sequator.

Nobody did this on purpose. Those tools were written by people solving their own problems on Windows, some of them two decades ago, and they are free. It does mean the standard beginner advice is written for a machine you do not own, and working out what to use instead is harder than it should be.

Here is what I found.

Our recommendation

For most people the answer is Akastroid: one app for deep sky, planets, the Moon and the Sun, on Mac, Windows and Linux. You drop in your frames and it grades, calibrates, stacks, removes the gradient, calibrates the colour and sharpens, with no settings to choose. The usual route needs four to six separate programs for the same result.

On the same Orion stack, Akastroid’s automatic finish measured a signal-to-noise of 402 against 87 for Siril’s standard workflow, with a sky gradient of 2.6% against 21.6% (the full comparison). It is free to try on your own data.

Choose PixInsight if you want to control every step by hand and will spend months learning it, or Siril if you want free software and are happy to learn the steps. The rest of this guide compares them in detail.

What runs natively on macOS

Siril. Free, open source, and the best starting point for deep sky on a Mac. Calibration, registration, stacking and a full post-processing set, with a scripting language that can run an entire session unattended. Apple silicon build available. Capability is not the problem. Siril does what you tell it and nothing else, and the scripts in the manual assume you already know which one matches your data.

PixInsight. Around €300, cross-platform, and the most capable program in the field. It also takes months to learn. Its own community will tell you it is not a first program.

GraXpert. Free, open source, cross-platform. Gradient removal and optional denoising. Not a stacker; it fixes one specific problem in an image you already have.

Starnet++. Free star removal that runs on macOS. It is one step in a workflow, not a whole workflow.

Astro Pixel Processor. Paid, cross-platform, Java-based. Well regarded for mosaics in particular.

Akastroid. What we make. Native on macOS including Apple silicon, deep sky and planetary in one program, free to try. More on where it fits below.

What does not, and what people try instead

DeepSkyStacker is Windows-only and has been since 2004. There is no Mac version and there is no plan for one.

AutoStakkert! is Windows-only. It is also the standard for planetary and lunar stacking, so this is the one Mac users miss most.

RegiStax is Windows-only and unmaintained since 2011.

Sequator is Windows-only. For wide-field nightscapes on a Mac, Starry Landscape Stacker is the usual answer instead. It is Mac-only, paid, and does the same job.

The usual advice is “just run it under Wine” or “use CrossOver” or “install Whisky”. Here is what that is like in 2026, particularly on Apple silicon:

• Homebrew disabled the WineHQ casks in September 2026 over Gatekeeper signing.
• Apple’s Game Porting Toolkit, which several guides still reference, is not a general-purpose answer and has been through breaking changes.
• Whisky installs, but getting a working runtime under it is its own project.
• Rosetta 2 does not help. It translates Intel macOS binaries, not Windows ones.

We tried to get RegiStax running this way on an Apple silicon Mac for a comparison benchmark and gave up after an hour. It can be done, but “install Wine” is not a one-line answer and I would not plan a workflow around it.

A virtual machine with a real Windows licence does work: Parallels or UTM with Windows on ARM, plus x86 emulation for these particular programs. It costs money, disk and patience, and you are then maintaining a Windows install in order to process pictures.

“Runs on a Mac” is not the same as “usable on a Mac”

These get mixed up, and it costs people evenings.

Siril and PixInsight both run natively on Apple silicon, so the platform is not the issue there. But Siril hands you a script menu and a manual that assumes you already know which script matches your data, and PixInsight presents dozens of processes with dozens of parameters each and no default path through them. The documented route is WBPP, then DBE, then SPCC, then a stretch, then noise reduction, then masked deconvolution, and it is normal for that to take months to learn. Both are very good, and both take real time to learn.

So a Mac owner has two separate problems, and only one of them is about platforms:

1. The planetary gap, which is a platform problem. AutoStakkert, RegiStax, PIPP and WinJUPOS are Windows-only, all of them, so there is nothing native to learn even if you wanted to.
2. The learning curve, which is not. It is identical on a Mac and a PC, and it is the reason most people with a working telescope still have a folder of unprocessed frames.

Akastroid is aimed at both. It is native on macOS, and it is meant to give you an image on the first evening.

What this means in practice

Realistically, a Mac astrophotographer’s options are:

Deep sky: Siril free, PixInsight if you want no ceiling, Akastroid if you would rather the software made the routine decisions and showed you what it measured.

Planets and the Moon: this is where the gap is. AutoStakkert! plus RegiStax is the free standard and neither runs. Your options are a Windows VM, or a program that does lucky imaging natively. That is part of why we built planetary into Akastroid rather than leaving it to a second tool.

Nightscapes: Starry Landscape Stacker, Mac-only and paid, or Siril.

Where Akastroid fits

Akastroid is a native macOS application (Apple silicon and Intel) that handles both deep sky and planetary. Load a folder of sub-exposures or a planetary video and it works out which it is, measures your frames, and decides the calibration, stacking, gradient removal, color and stretch for itself. Each decision is shown with the numbers behind it, so you can check what it did.

It is not more capable than PixInsight. On a Mac, it replaces a Windows VM plus three downloads with one program, and you can get a first image the same evening.

It uses no AI. There is no neural network in it and no model file in the download. It measures your frames and does arithmetic on them, so nothing in the result was generated. We chose that on purpose. The AI sharpeners and star removers are good at what they do, but they produce plausible detail, and that is different from detail the camera recorded.

Free to try on your own data, nothing uploaded, no account.

Download for macOS · Compared against Siril, DeepSkyStacker and PixInsight

A note on Apple silicon

M-series Macs are very good for this work. Stacking is embarrassingly parallel and the unified memory means a 300-frame session does not thrash. Akastroid ships a native arm64 build; Siril, PixInsight and GraXpert all have Apple silicon builds too. The only thing Apple silicon makes worse is the emulation route, because you are now two translation layers away from a Windows binary instead of one.

If you are buying a Mac for astrophotography, memory matters more than cores. A long session’s calibration masters are the thing that fills RAM.