Comparison

AstroStacker vs Image Stack

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

AstroStacker

Enhance your night sky photos by stacking multiple exposures into a single, detailed image. This app automatically aligns stars, reduces noise, and offers tools to refine your astrophotography results directly on your iPhone or iPad.

Highlights
  • Stack multiple night sky photos
  • Automatic star alignment
  • Noise reduction for clearer images
  • Advanced editing tools
  • Support for calibration frames (Pro)
  • On-device processing
Features
Read 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: 1 free stack with up to 10 light frames, 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/

About

Image Stack

This app streamlines image processing by allowing batch conversion, resizing, and renaming. Apply presets, add watermarks, and adjust quality settings with ease. It's designed for efficient handling of multiple images across devices.

Highlights
  • Batch image conversion
  • Apply multiple presets
  • Rename files
  • Resize images
  • Add overlays/watermarks
  • Adjust quality and metadata
  • iCloud preset sync
Features
Read full description

Image Stack converts images using presets to change formats, resize, rename, and more—whether you’re processing one image or thousands, everything is ready with just a few taps. KEY FEATURES • Batch convert images into modern formats • Apply one or more presets to avoid repetitive work • Rename files with prefixes, suffixes, or replacements • Resize images to match your requirements • Add overlays such as watermarks • Adjustable quality and metadata options • Drag-and-drop simplicity • Presets sync via iCloud for all your devices • Ultra-fast processing • Works on both macOS and iOS and iPadOS IDEAL FOR • Photographers organizing shoots • Designers exporting assets • Content creators preparing media • Anyone converting or renaming small or large image sets Image Stack is free to download and use. You can work with the app for as long as you like. To unlock the full experience and remove trial limits—such as the daily image limit—you can activate the full version with a one-time in-app purchase. The purchase is valid across all versions of Image Stack, including Mac, iPhone, and iPad. Is there any feature you are missing? Let me know!

Screenshots

AstroStacker4 screens
Image Stack4 screens

Verdict

The call

The clearest difference is review sentiment: Image Stack at 100% against AstroStacker's 0%. AstroStacker's advantage is update cadence (every 2 weeks vs monthly). On price, ads, in-app purchases and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. AstroStacker sells 3 in-app purchases, starting at $12.99 per month and Image Stack sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

AstroStacker ships an update every 2 weeks, Image Stack monthly. The most recent releases landed on November 14, 2026 and October 31, 2026 respectively.

Scorecard2 real differences · 8 level
AstroStacker versus Image Stack: the parameters behind the verdict, then further details
ParameterAstroStackerImage Stack
PriceFreeFree
Rating1.1 (7 ratings) — better—
Positive reviews0.0% of reviews100.0% of reviews — better
Number of ratings7 — better—
Update frequencyEvery 2 weeks — betterMonthly
AdsNoNo
In-app purchasesYesYes
MonetizationFreemiumFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, Mac — better
Requires iOS17.0 — better18.0
Further details — not scored
Size17 MB13 MB
Age rating4+4+
DeveloperAhmed Al-MahmudDaniel Witt

Customer experience

AstroStacker

All ratings7 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews11 reviews
Positive0.0%
Neutral18.2%
Negative81.8%

Image Stack

Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

3 purchases

AstroStacker

Subscriptions2
  • AstroStacker app3 Days trial$12.991 Month
  • AstroStacker app3 Days trial$99.991 Year
One-time1
  • AstroStacker app$219.00
1 purchases

Image Stack

One-time1
  • Full Version$9.99

Questions

Is AstroStacker free?
AstroStacker is free to download, with in-app purchases available.
Is Image Stack free?
Image Stack is free to download, with in-app purchases available.
Do AstroStacker or Image Stack have ads?
Neither AstroStacker nor Image Stack shows ads.
Which is updated more often, AstroStacker or Image Stack?
AstroStacker ships an update every 2 weeks, and Image Stack monthly. Most recently, AstroStacker was updated on November 14, 2026 and Image Stack on October 31, 2026.

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