Eise.app  Easy Image Stacker Engine

AutoStakkert! vs Eise.app

Which planetary stacker should you use?

AutoStakkert! (by Emil Kraaikamp) has been the industry-standard planetary stacker for over a decade. The current stable release is AutoStakkert!4 4.0.11 (January 2024); 4.0.13 (February 2025) is a newer beta build. Eise.app is a newer browser-based alternative built for people who want to stack a video without installing anything. This page compares the two honestly so you can pick the right tool for your workflow.

Feature-by-Feature Comparison

When AutoStakkert! is the better choice

• You're on Windows and stacking is your main workflow. AutoStakkert! is fast, mature, and integrates well with the wider Windows astrophotography ecosystem (SharpCap, FireCapture, Registax).
• You already know it. Every tutorial, every YouTube video, every forum thread about planetary stacking references AutoStakkert!. If you have muscle memory for the workflow, there's no urgent reason to switch.
• You need very large drizzle or very heavy stacks. A native binary with a full desktop CPU/RAM budget can crunch through frame counts that a browser sandbox will struggle with.
• You want the most refined alignment-point implementation available. Emil has spent over a decade tuning AS!, and it shows in edge cases.

When Eise.app is the better choice

• You're new to planetary stacking. Eise.app was designed to work well with defaults. Frame ranking, cropping, alignment, and sensible sharpening are all set up out of the box - you can get to a decent result without knowing what "AP size" or "double stack reference" means yet. Compare to AutoStakkert!, which is powerful but has more settings to learn upfront.
• You're on macOS or Linux. No Wine, no CrossOver, no VM. Eise.app runs natively in the browser on Apple Silicon and Linux.
• You want to try stacking without committing to an install. Open the page, drop a file, see a result in seconds.
• You shoot planetary video with a phone or DSLR. AutoStakkert! reads SER and AVI natively, but MP4, MOV, and HEVC files (typical of iPhone, Android, and mirrorless cameras) only work after you separately download FFmpeg and drop ffmpeg.exe into the AutoStakkert! folder. Eise.app has that layer built in - the same phone clip just opens.
• You want stacking and post-processing in one tool. Wavelet sharpening, RGB alignment, deconvolution, and color adjustments are built in - no need to save a TIFF and open Registax or ImPPG afterwards.
• You want long-term insurance against a tool going stale. Eise.app is open-source under active development. If maintenance ever slows, the code is on GitHub and forkable. AutoStakkert! is closed-source and its blog has been quiet since around 2020 - the app still works well, but if you rely on it heavily and it ever stops running on a future OS update, you'd be stuck.
• You're stacking on a shared or work computer. Nothing to install, no admin rights needed.
• You want to try stacking on mobile. It's slower and RAM-constrained, but it does work on a modern phone or tablet.

Technical Differences

Architecture. AutoStakkert! is a native Windows application. It has direct access to the file system, full CPU threading, and OS-level memory. Eise.app runs in a browser sandbox: file access is user-initiated, memory is limited (~2-4 GB per tab depending on browser), and processing uses WebGPU compute shaders and WebAssembly. That trade-off buys cross-platform portability at some cost in peak throughput.

Alignment. Both tools use alignment-point-based local warping to compensate for atmospheric seeing across the frame. AutoStakkert!'s implementation is the more refined - years of tuning show up in edge cases (very low light, extreme seeing, dense AP grids). Eise.app implements the same core approach with WebGPU-accelerated template matching.

Post-processing. AutoStakkert! deliberately doesn't do post-processing - the assumption is you'll pass the stacked output to Registax (wavelets), ImPPG (deconvolution), or AstroSurface for sharpening. Eise.app bundles wavelet sharpening, deconvolution, and RGB alignment into the same session.

Video file support. AutoStakkert!3 and AS!4 read SER, AVI, FITS, and image files directly. For MP4, MOV, and HEVC video (typical of iPhone footage, DSLR/mirrorless clips, and Android recordings), AS! shells out to an external ffmpeg.exe that the user has to download separately and place in the same folder as the AutoStakkert! executable. Without that step, the file simply doesn't open. Variable-frame-rate MP4s from phones often still need a pass through PIPP first. Eise.app bundles FFmpeg-WASM inside the browser app: any supported video format works on drop without any extra downloads or file management.

Privacy. Both tools process your data locally. AutoStakkert! runs on your machine. Eise.app runs in your browser - nothing is uploaded to a server.

Try Eise.app

The fastest way to compare the two is to run the same SER or AVI through both.

See also

• Registax 6 vs Eise.app - the classic wavelet sharpener compared
• Planetary System Stacker vs Eise.app - the Python cross-platform alternative
• Full planetary stacking software comparison - all eight tools side by side