Stop struggling with complex astronomy software. AstroSky is the easiest way to open FITS files on Windows. Drag and drop your astronomical survey data, click Auto Enhance, and export wallpaper-quality images up to 8K — all in seconds, 100% offline, and no account required.
AstroSky is a professional-grade FITS file viewer for Windows 10 and 11 that transforms raw astronomical survey data into stunning, wallpaper-quality images — no PhD required. Think of it as the "Snapseed for astronomy": drag in a FITS file, click Auto Enhance, and get a beautiful image in under 200 milliseconds.
Unlike complex scientific tools like DS9 or PixInsight, AstroSky is built for instant visual gratification. It automatically analyzes your image's histogram and picks the optimal stretch algorithm, color map, and black/white points — all with one click. Power users can switch to Science Mode for advanced tools like moment maps, PV diagrams, RGB synthesis, and celestial object identification.
Your data stays private — AstroSky works 100% offline after installation from the Microsoft Store. No files are ever uploaded. No account, no telemetry, no subscription. Just free 30-day trial with all features unlocked, then a one-time purchase for lifetime access.
A clean, intuitive interface that makes FITS data exploration effortless — from import to export in seconds.
No steep learning curve. No manual required. Just drag, click, export.
Drag one or more FITS files (or an entire folder) directly into AstroSky. Files load in parallel with real-time progress indicators.
Hit the Auto button. AstroSky analyzes the histogram and automatically picks the optimal stretch algorithm, color map, and black/white points. Results in 200ms.
Export as PNG, JPEG, or FITS at resolutions from 1080p to 8K. Optional watermark with telescope details — perfect for AstroBin and CloudyNights.
Ready to try the best FITS viewer for Windows?
Free 30-day trial — no credit card, no account, fully offline.
Get AstroSky on Microsoft StoreAstronomy's Snapseed — simple, instant feedback, visually driven. Complex parameters hidden in advanced options, zero-barrier default experience.
Drag and drop multiple FITS files or entire folders. Parallel loading with real-time progress. Supports .fits, .fit, .fts extensions and multi-extension FITS files.
One-click Auto button analyzes histogram shape (unimodal/bimodal/long-tail) and automatically selects the optimal stretch algorithm, color map, and black/white point combination.
Choose from Viridis, Plasma, Inferno, Magma, Hubble Palette, and more. Each color map includes a gradient preview swatch. All maps are perceptually uniform and colorblind-friendly.
Real-time 256-bin histogram visualization with black/white point markers. Drag sliders and see instant 200ms preview refresh — no waiting.
Beauty Mode hides scientific noise for a clean creative experience. Science Mode expands full analysis tools — beam overlay, pixel readout, PV diagrams, channel maps — toggle in ≤100ms without reloading.
Assign R/G/B channels to different FITS images via hover buttons on thumbnails. Synthesize multi-band composite images with per-channel stretch and weight controls.
Export to PNG/JPEG/FITS with preset resolutions from 1080p to 8K. Optional watermark with telescope model, observation band, and integration time. Author signature support.
Auto-recognizes coordinates (Galactic/Equatorial) from WCS headers. Built-in offline database of 800+ celestial objects (Messier, NGC, IC) with plain-language descriptions. Aitoff projection sky minimap.
Searchable three-column table (keyword/value/comment) for all FITS header entries. One-click value copy. Multi-extension support with extension switcher.
Moment maps, image algebra, position-velocity diagrams, channel maps for data cubes (NAXIS=3). Beam ellipse overlay from BMAJ/BMIN header keywords. Pixel value readout on hover.
Full parameter undo/redo stack via Ctrl+Z / Ctrl+Y. Every adjustment is tracked and reversible. Non-destructive processing — original FITS data is never modified.
Full UI localization for English, Japanese, German, French, Spanish, Portuguese, and Russian. Switch languages at any time from Settings without restart.
All image processing runs entirely on your local machine. No account required. No internet connection needed after installation.
All FITS loading, stretch processing, and rendering runs locally. The app works fully offline after installation from the Microsoft Store.
Your FITS files and rendered images are processed in memory on your own machine. No telemetry, no analytics, no data transmission of any kind.
No sign-up, no login, no subscription. Download from the Microsoft Store and start exploring astronomical data immediately.
Image rendering powered by SkiaSharp for fast, high-quality output. Optimized for large FITS files from modern astronomical surveys.
Start your free 30-day trial today. No credit card. No account. Fully offline.
Download from Microsoft StoreAstroSky ships with full UI localization for seven languages, switchable at any time from Settings.
AstroSky is a professional FITS image viewer for Windows 10 and 11 that turns raw astronomical survey data into stunning, wallpaper-quality images. It supports batch FITS import, one-click Auto Enhance, 12+ perceptually-uniform color maps, and exports up to 8K resolution — all 100% offline. Think of it as the easiest way to open FITS files and make them look beautiful.
Yes — AstroSky offers a free 30-day trial with all features fully unlocked. No credit card or account required. After the trial, a one-time purchase gives you lifetime access. There is no subscription — you buy it once, you own it forever.
Absolutely. AstroSky is a dedicated FITS file viewer for Windows that opens .fits, .fit, and .fts files directly. Unlike generic image viewers, AstroSky understands FITS headers, WCS sky coordinates, and multi-extension data — it's the easiest way to view and convert FITS files on Windows.
Yes. After installation from the Microsoft Store, AstroSky works 100% offline. All image processing runs locally on your device — no internet connection is needed. Your FITS files never leave your computer.
AstroSky supports .fits, .fit, and .fts files, including multi-extension FITS (MEF) and data cubes (NAXIS=3) for spectral data visualization like radio astronomy cubes.
Select any image in the Gallery, click Export Image, and choose from resolution presets: 1080p, 1440p, 4K, 5K, or 8K. Pick PNG or JPEG format, optionally add a watermark with telescope details, and click Export. Your wallpaper-ready image is saved instantly.
Beauty Mode (default) shows a clean, minimal interface with just Auto, Color Map, and Export — perfect for creating wallpapers. Science Mode expands full analysis tools: beam overlay, pixel readout, sky coordinates, PV diagrams, channel maps, moment maps, and image algebra. You can switch in under 100ms without reloading images.