Can You Process Astrophotos Online, Without a Computer? (2026)

A particular kind of person asks this question. They bought a Seestar, a Dwarf or a Vespera because it works from a phone, they have been happy with the pictures the app makes, and then they read that the saved frames on the device are better than the app’s live stack. That is true, by a wide margin. So they look for a way to process those frames.

Every answer they find starts with “install this on your computer”. They do not have one, which is why they bought a smart telescope.

This is what exists for them in 2026, including what does not exist yet.

Our recommendation

For most people the answer is Akastroid: one app for deep sky, planets, the Moon and the Sun, on Mac, Windows and Linux. You drop in your frames and it grades, calibrates, stacks, removes the gradient, calibrates the colour and sharpens, with no settings to choose. The usual route needs four to six separate programs for the same result.

On the same Orion stack, Akastroid’s automatic finish measured a signal-to-noise of 402 against 87 for Siril’s standard workflow, with a sky gradient of 2.6% against 21.6% (the full comparison). It is free to try on your own data.

Choose PixInsight if you want to control every step by hand and will spend months learning it, or Siril if you want free software and are happy to learn the steps. The rest of this guide compares them in detail.

The short answer

There is no mature, general “upload your FITS, get a finished image” service for amateur deep-sky data. Not from ZWO, not from the big processing tools, not from anyone with a track record. What exists is:

• The telescope’s own app. Real-time stacking on the device. It is good, and it is the reason you bought the telescope. It is limited in three specific ways that a desktop stack of the saved frames is not.
• Desktop software on a computer you borrow. Every serious tool (Siril, PixInsight, DeepSkyStacker, Akastroid) runs on a Mac or PC. A family laptop with 20 GB free will do a Seestar session in a few minutes.
• A handful of one-off web tools that stack a few JPEGs in the browser. They do not read FITS, do not calibrate, do not reject frames, and are not built for hundreds of files. Fine for a Milky Way phone shot, not for 540 sub-exposures.
• Cloud processing that is still being built, ours among them. More below.

Why it does not exist yet

There are three reasons, and none of them is that nobody thought of it.

The upload. A 90-minute Seestar session is about 540 FITS files and roughly 10 GB. On home Wi-Fi that is 10 to 20 minutes; on hotel or mobile data it is an evening. A service that asks you to move that much data has to make the upload resumable, compressible and unattended, or the first dropped connection kills it.

Privacy. Most astrophotographers who care about processing also care that their frames stay theirs. A cloud service has to say plainly what it keeps, for how long, and what it will never do with your data, and then be checkable on it.

Cost. Storing 10 GB per user per session forever costs real money. Processing it costs a few minutes of a server. The service has to delete raw frames on a schedule you agree to, or its storage bill sinks it.

None of these is hard. They are the things a quick weekend project skips, which is why the weekend projects have not lasted.

What cloud processing would need to do

If you are evaluating one, ours or anyone else’s, these are the questions that separate a product from a demo:

1. Does it read your telescope’s files directly? Seestar and Dwarf write raw Bayer FITS with quirks in the headers. A service that asks you to convert first has already lost the phone-only user.
2. Does it grade and reject frames? The point of processing the saved frames instead of trusting the live stack is throwing out the cloudy minute 40. If the service averages everything, you gained nothing.
3. Does it handle field rotation? Every smart telescope is on an alt-azimuth mount. Translation-only alignment smears the result, and the smear looks like bad focus rather than an error.
4. Do you get the linear data back, or just a JPEG? A 16-bit TIFF or FITS lets you finish the image elsewhere later. A JPEG is a dead end.
5. What happens to your frames afterwards? You want a date, not a policy page.
6. Can you resume an upload? If not, you will find out on hotel Wi-Fi.

What we are building

Akastroid is a desktop app that does all of the above on your own computer and uploads nothing. That makes it the wrong tool for someone with no computer.

So we are building a cloud version: the same engine, running on a machine we operate. You upload from a phone or tablet, get an email when the finished image is ready, and download three styles and a 16-bit TIFF. Raw frames are deleted 30 days after upload and results after 90. About $12 a month for 15 sessions, cancel any time. Nothing about the desktop app changes.

It is not built yet. Whether it gets built depends on how many people sign up. The two optional questions on the form (what you image with, and whether you have a computer) are how we tell “would be nice” from “this is the only way I could use it”.

Join the cloud waitlist. You get one email when it launches, nothing else.

What to do tonight

If you have a smart telescope and no computer:

1. Turn on Save every frame anyway. The files cost you nothing and they are the only thing that can be reprocessed later. A session without saved frames stays forever at the quality the app gave it.
2. Copy the target folders off the device to a phone, a USB stick or a cloud drive. The device’s storage is not a backup.
3. Borrow a computer once: a friend’s laptop, a library machine, a work computer at lunch. Akastroid’s free version has every feature and does a Seestar session in a few minutes. So does Siril, once you have learned it. Doing this once tells you whether the difference matters to you.
4. If it does, and borrowing is not a long-term plan, put your name on the list.

Whatever tool you end up using, it can only work with frames you saved, so save them tonight.