01 · alignment
Align the sky
Stars stay registered across every frame, even when your setup shifts slightly between exposures.
Sub-pixel star alignment
Astrophotography stacking for iPhone
Stack noiseinto stars.
Turn multiple photos of stars, night skies, the Moon or planets into one clear, detailed image—right on your iPhone.
More signal. Less noise.
The best night-sky photois rarely a single frame.
Astrophotography stacking combines multiple exposures of the same night sky. Astro Stacker aligns the frames, strengthens repeated light and reduces random noise so stars, skies, the Moon and planets come through more clearly.
02 · stacking
Reveal hidden detail
Combine repeated signal to reduce grain, hot pixels and unwanted trails while keeping celestial detail.
Six stacking methods
03 · finishing
Finish on iPhone
Refine colour, contrast and structure with astronomy-focused styles, then export at full resolution.
Private, on-device workflow
Start under the stars
Try your firststacks free.
Learn the workflow for free. Upgrade when you are ready for larger sessions, advanced formats and complete calibration.
FreeNo card needed
$0forever
Start with the sky you have.
Everything you need to discover what stacking can reveal.
- 3 stacking sessions every 7 days
- Up to 10 light frames per stack
- Standard image formats
- 3 saved results
- Private, on-device processing
Astro Stacker ProFull darkroom
Go deeper.
The complete mobile darkroom for deeper sessions.
Monthly
$12.99per monthAnnualRecommended
$99.99per yearLifetimePay once
$219.00one-time- Unlimited frames and stacking sessions
- RAW, Apple ProRAW and native FITS
- Dark, flat, dark-flat and bias calibration
- Advanced alignment and six stacking methods
- 16-bit exports and unlimited history
US App Store reference prices are $12.99/month, $99.99/year or $219.00 lifetime. Apple shows your local price and confirms it before purchase.
Questions under the stars
Everything you need to knowbefore your first stack.
What is astrophotography stacking?
Astrophotography stacking combines multiple exposures of the same night sky. Astro Stacker aligns the frames, strengthens repeated light and reduces random noise so stars, skies, the Moon and planets come through more clearly.
Can I stack astrophotography photos directly on an iPhone or iPad?
Yes. Choose a sequence from Photos or Files and Astro Stacker aligns, calibrates, stacks, enhances and exports the result on your iPhone or iPad.
How does stacking reduce noise in night-sky photos?
Stars and celestial detail repeat across aligned frames while much sensor noise varies from frame to frame. Combining the frames strengthens the repeated signal and reduces random grain, without promising that every artefact will disappear.
How many photos should I stack?
Start with several consistent, sharp exposures of the same scene. More well-matched frames can improve the result, but quality and consistency matter too. Free supports up to 10 light frames per stack; Pro removes the frame limit.
What can I photograph with Astro Stacker?
Stack stars, the Milky Way, deep-sky objects, the Moon and planets. Use photos from your iPhone or iPad, or import compatible image files captured with a camera or smart telescope.
Do I need a computer to stack photos?
No. Astro Stacker aligns, calibrates, stacks and enhances your images on iPhone or iPad, so you can finish a session without moving it to a desktop workflow.
Which image formats can I import and export?
Free works with standard photo formats. Pro adds RAW, Apple ProRAW and native FITS import. You can export JPG, PNG, TIFF and FITS, with 16-bit exports on Pro.
What are dark, flat, bias and dark-flat calibration frames?
Dark frames help correct thermal signal and hot pixels, flat frames help correct vignetting and dust, bias frames capture readout offset, and dark-flat frames calibrate flat exposures. Calibration is optional when you are learning and available in Pro.
Can I stack files from a camera or smart telescope?
Yes, Pro can import compatible RAW and FITS files through Files. Astro Stacker processes the files you provide; it does not claim universal hardware compatibility or control the capture device.
What is included in the free version?
Free includes up to 10 light frames per stack, 3 stacking sessions every 7 days, standard photo formats and 3 saved results.
What does Astro Stacker Pro unlock?
Pro adds unlimited stacking sessions and frames, RAW, Apple ProRAW and FITS import, dark/flat/dark-flat/bias calibration, advanced alignment controls, 16-bit exports and unlimited history.
Can I use Astro Stacker offline?
Yes. The core stacking and editing workflow runs on your iPhone or iPad, and your images do not need to be uploaded. Optional account features, history sync, purchase verification and operational diagnostics use an internet connection.
Which devices can run Astro Stacker?
Astro Stacker supports iPhone and iPad running iOS or iPadOS 17.0 or later.