TLDR
Pick based on your target objects and how much manual control you want. Deep-sky imagers who stack hundreds of subframes lean toward dedicated integration tools with strong calibration, while planetary shooters need lucky-imaging stackers built for video. Weigh your operating system, budget, and tolerance for a steep interface before committing.
Deep-sky astrophotographers who capture many long exposures and want full control over calibration, integration, and gradient removal.
Astrophotography processing is really two jobs: combining many exposures to beat down noise (stacking and integration), then stretching and cleaning the result to reveal faint detail. The tool you need depends heavily on whether you shoot deep-sky targets (galaxies, nebulae) or planetary and lunar video.
Deep-sky work rewards careful calibration with darks, flats, and bias frames, plus gradient removal for light pollution. Planetary imaging is a different discipline built around lucky imaging, where software picks the sharpest frames from thousands in a video file.
Weigh your operating system first (some flagship tools are Windows-only), then your budget, then how much you want to learn. A free stack of DeepSkyStacker and Siril handles a lot before you ever pay for anything.
best software for astrophotography processing Tools compared
Filter by what you care about. Every tool stays on the page.
| Tool | Price | Image Stacking | Calibration Frames | Noise Reduction | Platform Support | Scripting & Automation | Learning Curve |
|---|---|---|---|---|---|---|---|
| PixInsight | From $290 | Yes | Yes | Yes | Yes | Yes | No |
| DeepSkyStacker | Free | Yes | Yes | Limited | Limited | Yes | Yes |
| Siril | Free | Yes | Yes | Yes | Yes | Yes | Limited |
| Adobe Photoshop | From $22.99/mo | No | No | Limited | Yes | Limited | Limited |
| AstroPixelProcessor | From $75/yr | Yes | Yes | Yes | Yes | Limited | Limited |
| Sequator | Free | Yes | Limited | Yes | Limited | Limited | Yes |
| Starnet++ | Free | No | No | Yes | Yes | Limited | Limited |
| AutoStakkert! | Free | Yes | Limited | Limited | Limited | Yes | Limited |
| RegiStax | Free | Yes | Limited | Limited | Limited | Limited | Limited |
| Nebulosity | From $95 | Yes | Yes | Limited | Limited | Limited | Yes |
| GraXpert | Free | No | Limited | Limited | Yes | Yes | Yes |
| Topaz DeNoise AI | From $12/mo | No | No | Yes | Yes | Limited | Yes |
| PhotoPills | From $10.99 | No | No | No | Limited | No | Yes |
| Fitswork | Free | Yes | Limited | Limited | Limited | Limited | Limited |
| ImagesPlus | From $60 | Yes | Yes | Yes | Limited | Limited | Limited |
Highlighted rows are featured placements. Competitor details are set by each platform, so confirm on their site before buying.
The 15 best best software for astrophotography processing tools
PixInsight
From $290PixInsight is the most complete platform for deep-sky image processing, covering everything from calibration and integration to noise reduction, deconvolution, and color work. It uses a script-driven, node-based approach that rewards learning but has a steep curve. Most advanced imagers treat it as the reference standard for pulling detail out of stacked data.
Pros
- Handles the full pipeline from raw frames to finished image
- Powerful integration and stacking with fine control
- Strong noise reduction and deconvolution tools
- Active development and a large user community
Cons
- Steep learning curve for newcomers
- Interface feels dated and unintuitive
- One-time price plus paid major upgrades
Best for: Advanced deep-sky imagers who want end-to-end control
DeepSkyStacker
FreeDeepSkyStacker, often called DSS, is a long-running free utility that handles registration, calibration, and stacking of light, dark, flat, and bias frames. It is a common first stop for beginners because it automates alignment and integration without cost. Final tuning usually happens in another editor, since DSS is not built for detailed post-processing.
Pros
- Completely free to use
- Simple workflow for beginners
- Supports full calibration frame sets
- Handles alignment and stacking automatically
Cons
- Windows only
- Minimal post-processing tools
- Development has slowed
Best for: Beginners stacking their first deep-sky sets on Windows
Siril
FreeSiril is a free, cross-platform tool that covers preprocessing, registration, stacking, and a good range of post-processing including gradient removal and color calibration. It offers both a graphical interface and scriptable commands for repeatable workflows. It has become a popular free alternative for imagers who want more than a stacker but do not want to pay for a suite.
Pros
- Free and open source
- Runs on Windows, macOS, and Linux
- Scriptable for automated pipelines
- Covers stacking plus real post-processing
Cons
- Interface takes time to learn
- Fewer advanced tools than paid suites
Best for: Budget-minded imagers wanting stacking and processing in one
Adobe Photoshop
From $22.99/moPhotoshop is not built for astronomy, but its layers, masking, and curves make it a favorite for final aesthetic work after stacking. Many imagers export from a dedicated stacker, then use Photoshop with astro plugins for star handling, gradients, and color. It has no native calibration or stacking, so it sits at the end of the workflow.
Pros
- Unmatched layer and masking control
- Huge library of astro plugins and actions
- Precise color and contrast adjustments
- Cross-platform with strong support
Cons
- No stacking or calibration built in
- Subscription only
- Learning curve for astro techniques
Best for: Final stretching, color, and finishing after stacking
AstroPixelProcessor
From $75/yrAstro Pixel Processor, or APP, is a deep-sky application covering calibration, registration, integration, and post-processing with a focus on multi-panel mosaics and light-pollution removal. It aims to be more approachable than PixInsight while still offering advanced control. It is sold with rental or ownership licenses plus a trial.
Pros
- Excellent mosaic and panel stitching
- Strong gradient and light-pollution removal
- More approachable than heavier suites
- Rental or ownership licensing options
Cons
- Paid license required after trial
- Interface can feel busy
- Smaller community than PixInsight
Best for: Imagers doing mosaics and dealing with light pollution
Sequator
FreeSequator is a free Windows tool that stacks star trackless landscape astrophotos, aligning the sky while keeping the foreground fixed. It is popular for Milky Way and nightscape work because it is fast and easy for beginners. It is not designed for detailed deep-sky processing through a telescope.
Pros
- Free and easy to use
- Great for Milky Way and nightscapes
- Handles foreground and sky separately
- Fast processing
Cons
- Windows only
- Limited to wide-field style shots
- Few advanced controls
Best for: Wide-field Milky Way and landscape astrophotography
Starnet++
FreeStarNet Software provides StarNet2 for star removal and DeepSNR for noise reduction, available as PixInsight modules, Photoshop plugins, and command-line tools. Removing stars lets you process nebulosity separately, which is a key step in modern deep-sky editing. It is a specialized helper rather than a full processing suite.
Pros
- Very effective automated star removal
- Works inside PixInsight, Photoshop, and Siril
- Adds AI noise reduction with DeepSNR
- Free command-line and module options
Cons
- Not a standalone full processor
- Needs a host app for best workflow
Best for: Separating stars from nebulosity during processing
AutoStakkert!
FreeAutoStakkert! specializes in stacking video captures of the Moon, planets, and Sun using lucky imaging, grading and aligning thousands of frames automatically. It is fast and highly regarded for high-resolution planetary results. It focuses on stacking, with sharpening usually handled afterward in a wavelet tool.
Pros
- Best-in-class planetary and lunar stacking
- Handles large video files efficiently
- Free to use
- Automatic frame grading and alignment
Cons
- Windows focused
- Not for deep-sky imaging
- Needs a separate sharpening step
Best for: Planetary, lunar, and solar lucky-imaging stacks
RegiStax
FreeRegiStax is a long-standing free tool for aligning and stacking planetary and lunar video, with wavelet sharpening that many imagers still use even alongside other stackers. It brings out fine surface detail on the Moon and planets. Development has largely stalled, but the wavelet stage keeps it in use.
Pros
- Famous wavelet sharpening tools
- Free to use
- Effective for planetary and lunar detail
- Handles video stacking
Cons
- Windows only
- No longer actively developed
- Dated interface
Best for: Wavelet sharpening of planetary and lunar images
Nebulosity
From $95Nebulosity from Stark Labs combines camera capture with calibration, stacking, and basic processing in one program aimed at beginner and intermediate imagers. It supports many cameras and offers a simpler path than the big suites. It is a paid but low-cost option that covers acquisition and early processing.
Pros
- Combines capture and processing
- Beginner-friendly workflow
- Broad camera support
- Low one-time price
Cons
- Limited advanced processing
- Interface feels dated
- Smaller user base now
Best for: Beginners wanting capture plus basic processing together
GraXpert
FreeGraXpert is free open-source software built to remove background gradients caused by light pollution, vignetting, or sky glow. It runs standalone and also fits into workflows alongside other processors. Newer versions add AI-based background extraction and denoising, but its core job is clean gradient removal.
Pros
- Free and open source
- Excellent automated gradient removal
- Cross-platform standalone app
- Added AI background and denoise features
Cons
- Narrow purpose
- Not a full processing suite
Best for: Removing light-pollution gradients before further editing
Topaz DeNoise AI
From $12/moTopaz Labs now bundles its denoise and sharpen models into Topaz Photo and Studio, offering AI noise reduction and detail recovery useful in the finishing stage of astrophotos. It is a general photo tool, not astronomy-specific, so it lacks stacking and calibration. Many imagers apply it carefully to control noise without smearing star fields.
Pros
- Strong AI noise reduction
- Good detail and sharpening recovery
- Works as a finishing-stage tool
- Available on desktop and web
Cons
- Not built for astronomy
- Can distort stars if overused
- Subscription pricing on newer plans
Best for: Noise reduction and sharpening in the finishing stage
PhotoPills
From $10.99PhotoPills is a mobile planning tool that helps you find where and when to shoot the Milky Way, Moon, and sun using augmented reality and detailed ephemeris data. It does not process images, but it is widely used by nightscape photographers to plan sessions. Think of it as pre-shoot support rather than post-processing.
Pros
- Excellent Milky Way and Moon planning
- Augmented reality alignment view
- Detailed ephemeris and calculators
- One-time mobile purchase
Cons
- Not an image processor
- Mobile only
- Learning curve for all features
Best for: Planning nightscape and Milky Way shoots before capture
Fitswork
FreeFitswork is a free Windows program for working with FITS files, offering stacking, alignment, and various correction and processing functions. It is handy for quick fixes, format conversion, and basic processing of astronomical data. It is a niche utility rather than a polished full suite.
Pros
- Free to use
- Strong FITS file support
- Includes stacking and corrections
- Useful for quick processing tasks
Cons
- Windows only
- Dated interface
- Limited documentation in English
Best for: FITS handling and quick astro image fixes
ImagesPlus
From $60ImagesPlus is a long-running paid application that offers camera control, calibration, stacking, and a wide set of processing tools for deep-sky work. It was popular with DSLR imagers and still carries a deep feature set. Its interface and workflow feel dated compared with newer suites.
Pros
- Covers capture through processing
- Deep set of processing tools
- Camera control included
- One-time purchase
Cons
- Windows only
- Dated and complex interface
- Smaller community today
Best for: DSLR imagers wanting capture and processing in one package
How to choose the right processing tool
Start with your imaging type. Deep-sky shooters need capable calibration and integration, so tools like PixInsight, Siril, or Astro Pixel Processor fit. Planetary and lunar imagers work from video and should look at AutoStakkert!, RegiStax, and PIPP for pre-processing.
Check the platform. PixInsight runs on Windows, macOS, and Linux, but several stackers (DeepSkyStacker, AutoStakkert!) are Windows-only. Mac and Linux users often build a workflow around Siril and GraXpert, both of which are free and cross-platform.
Be honest about the learning curve. PixInsight is powerful but has a reputation for being unintuitive. If you want faster results, Siril's scripting and StarTools' guided workflow get you to a decent image sooner.
Key features to look for
Calibration support matters most for signal quality. Make sure the tool handles darks, flats, and bias/dark-flat frames properly, and can build master frames. Poor calibration shows up as amp glow, vignetting, and hot pixels that no amount of editing fully fixes.
Gradient and light pollution removal is essential for anyone imaging from suburbs or cities. GraXpert (now integrated into several workflows) and PixInsight's DBE/GradientCorrection are the common choices. Star removal tools like StarNet++ let you process stars and nebulosity separately, which is close to mandatory for modern deep-sky editing.
Building a full workflow on a budget
You can process serious images for free. DeepSkyStacker or Siril handles stacking and calibration, GraXpert removes gradients and denoises, StarNet++ separates stars, and GIMP finishes the edit. Many imagers run this chain for years before buying anything.
When you do pay, prioritize one tool that removes friction. PixInsight (roughly 290 euros) is the usual step up for deep-sky. Photoshop with astronomy actions works well for the final stretch and creative editing if you already own a Creative Cloud subscription.
Frequently asked questions
What is the best software for beginners?
Siril and DeepSkyStacker are the common starting points because they are free, well documented, and handle calibration and stacking without much setup. Pair either with GIMP or Photoshop for the final stretch. StarTools is also beginner-friendly thanks to its guided, non-destructive workflow, though it costs a modest one-time fee.
Do I really need PixInsight?
No. PixInsight is powerful and widely used for deep-sky work, but it is not required. Many imagers produce excellent results with Siril, GraXpert, and StarNet++, all free. Buy PixInsight when you want more control over noise, gradients, and deconvolution than the free tools give you, and you're willing to learn its interface.
What software is best for planetary imaging?
Planetary and lunar imaging uses lucky imaging from video files. AutoStakkert! is the standard for aligning and stacking the sharpest frames, RegiStax handles wavelet sharpening, and PIPP is useful for pre-processing and centering. WinJUPOS helps with derotation of planets like Jupiter that rotate quickly during capture.
Can I process astrophotos in regular Photoshop?
Yes, but Photoshop alone cannot stack or calibrate raw astro data well. Use a dedicated stacker first (DeepSkyStacker, Siril, or Astro Pixel Processor), then bring the integrated file into Photoshop for stretching, color, and star handling. Astronomy-specific action sets and plugins make this much smoother.
Are free tools good enough for serious results?
Absolutely. A chain of Siril, GraXpert, and StarNet++ plus GIMP covers stacking, calibration, gradient removal, denoising, and star separation at zero cost. Paid tools mostly save time and add refinement rather than being strictly necessary for good images.
Does this software work on Mac and Linux?
It varies. PixInsight, Siril, and GraXpert are cross-platform. DeepSkyStacker, AutoStakkert!, RegiStax, and several others are Windows-only, though some run under Wine or a virtual machine. Mac and Linux users typically build around the cross-platform options.
What does astrophotography software cost?
Prices range widely. Siril, DeepSkyStacker, GraXpert, AutoStakkert!, and RegiStax are free. StarNet++ is free. StarTools and Astro Pixel Processor are one-time purchases in the tens of dollars/euros. PixInsight is around 290 euros as a perpetual license. Photoshop is subscription-based through Creative Cloud.
The bottom line
If you want maximum control and don't mind a hard learning curve, PixInsight is the standard for deep-sky work. Beginners should start with the free DeepSkyStacker plus GIMP or Siril, then graduate to paid tools once they understand calibration. Download a trial of one integration tool and one editor before you spend anything.