SynLink vs Astro Stacker
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SynLink
This professional controller facilitates astrophotography by offering broad compatibility with major camera brands and astronomical equipment. Its design emphasizes simplicity, restraint, and modernity for an intuitive user experience.
- Broad camera compatibility (Fujifilm, Canon, Nikon, Sony)
- Supports astronomical cameras
- Controls equatorial mounts
- Manages filter wheels and focusers
- Modern and simple interface
Read full descriptionHide full description
It offers seamless compatibility with most mainstream cameras, including Fujifilm, Canon, Nikon, and Sony, as well as the majority of astronomical cameras, equatorial mounts, filter wheels, focusers, rotators, and flat panel devices on the market. SynLink is being developed by following the design philosophy of simplicity, restraint, and modernity.
Astro Stacker
Transform your smartphone into a powerful astrophotography tool. This app uses advanced algorithms to combine multiple night sky photos, reducing noise and revealing hidden celestial details for professional-quality results.
- Advanced stacking algorithms (Average, Median, Maximum, Minimum)
- Intelligent and manual image alignment
- Real-time processing and progress tracking
- On-device processing, no cloud upload
- Export high-resolution stacked images
- Detailed processing insights and logs
Read full descriptionHide full description
Stack your night-sky photos into one cleaner, more detailed image, right on your iPhone or iPad. Astrophotography stacking combines many exposures of the same sky. Astro Stacker finds the stars in every frame, lines them up and combines them, so random noise falls away and faint stars, the Milky Way and deep-sky targets come through. HOW IT WORKS 1. Take several separate photos of the same patch of sky from a tripod or stable surface. 2. Import them from Photos or Files into a Deep Sky Studio project. 3. Pick a stack mode and tap Stack. 4. Finish the result with Auto Stretch, styles and colour tools, then save or export. THREE SIMPLE STACK MODES - Quick: averages every frame for a fast first look. - Quality (default): rejects outliers such as plane and satellite trails, and leaves out the weakest frames. - Max Detail: the slowest and most selective mode, with finer alignment. AUTOMATIC STAR ALIGNMENT Stars are detected and matched in every frame, with sub-pixel alignment and a quality check for each frame. Stacking needs clear stars in your photos to line them up. CALIBRATION FRAMES (PRO) Add darks, flats, dark-flats and bias frames to correct hot pixels, thermal noise, vignetting and dust. Astro Stacker sorts frames by file name and exposure, so files named "dark" or "flat" are picked up for you. FINISH IN THE SAME APP - Auto Stretch to bring faint signal into view - Gradient removal for light pollution and uneven skies - Local contrast, vibrance, levels and per-channel colour balance - Styles: Natural, Nebula Pop, Cosmic Drama and Scientific, each with a strength slider - Before-and-after comparison - Quick Enhance for a single photo you've already taken FILES IN AND OUT - Import: photos from your library on Free; camera RAW, Apple ProRAW and FITS on Pro - Export: JPG, PNG, TIFF and FITS, with 16-bit export on Pro ON-DEVICE Stacking and editing run on your iPhone or iPad. You don't need a computer, and your source frames are not uploaded to stack them. An optional account backs up finished results. FREE AND PRO Free: up to 10 light frames per stack, 3 stacks every 7 days and 3 saved results. Pro: unlimited frames and stacks, RAW, ProRAW and FITS import, calibration frames, 16-bit export and unlimited history. Choose monthly, annual or a one-time lifetime purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period, and you can manage them in your App Store account settings. GOOD TO KNOW - Moon, planet and solar stacking (Planet Lab) is coming soon. Today's stacking needs stars to align on. - Colour FITS files from one-shot-colour cameras are not debayered yet. - Star-trail stacking isn't supported, because every stack is aligned on the stars. Guides to capturing and stacking: https://astrostacker.co/guides Privacy Policy: https://astrostacker.co/privacy Terms of Use: https://astrostacker.co/terms Apple Standard EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is rating: SynLink at 4.3 against Astro Stacker's 1.0. SynLink also leads on in-app purchases (none vs 3) and device support (4 vs 2). On price, ratings volume, update cadence and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Astro Stacker sells 3 in-app purchases, starting at $12.99 per month. SynLink asks for nothing beyond the download.
SynLink holds the better App Store score, 4.3 against 1.0. Both are backed by a comparable volume of ratings — 3 and 5 respectively.
Both ship on a similar rhythm, roughly fortnightly. The most recent releases landed on October 25, 2026 and October 28, 2026 respectively.
| Parameter | SynLink | Astro Stacker |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (3 ratings) — better | 1.0 (5 ratings) |
| Positive reviews | — | 0.0% of reviews |
| Number of ratings | 3 | 5 — better |
| Update frequency | Fortnightly | Fortnightly |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 221 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Suzhou UMa Technology Co., Ltd | Ahmed Al-Mahmud |
Customer experience
SynLink
Astro Stacker
In-app purchases
SynLink
No in-app purchases
Astro Stacker
- AstroStacker app$12.991 Month
- AstroStacker app$99.991 Year
- AstroStacker app$219.00







