Siril is a software application for astrophotography, which allows pre-processing and processing of images from any type of camera (CCD, planetary camera, webcam etc.). The images must be converted to 32-bit FITS format which is the format used natively by Siril. It is also possible to use the SER format (limited to 16 bits), generally used during "fast" planetary or deep sky acquisitions, without prior conversion.
It is based on the GNOME environment and therefore can be run on many systems like Linux, FreeBSD, MacOS, and Windows.
It is free software distributed under the terms of the GNU GPL.
The project was launched in 2005 by François Meyer. Siril was initially developed as a clone of Christian Buil's IRIS software, in order to overcome the lack of astronomical image processing software under the Linux system; hence the name SIRI-L (IRIS for Linux). A new team took over development of the project in 2012 after a pause from 2007.
What is Siril?
Siril is an open-source science & math program for Windows from Free-Astro. It ranks 50th by popularity among science & maths in this catalogue. It is written in C and C++. Besides Windows, it is available for GNU/Linux, macOS and FreeBSD.
Installation and requirements
Official installers exist for 64-bit as EXE (Inno Setup). The main installer is 79.6 MB. Installation asks for administrator rights. The installer supports unattended (silent) installation.
Updates and version history
The current version is 1.2.6, released on January 22, 2025. 3 versions are listed since November 13, 2023, each with links to its own installer files. That is about 2.5 releases a year. The last update is more than a year old.
Popularity and file types
The Chocolatey package has been downloaded 1,679 times. Wikipedia has an article about it in 3 of our languages. Similar programs include Stellarium, KiCad and Quarto.
Pros / Cons
Pros
- Open source: the code can be inspected and built by anyone
- Documented silent install
- Also runs on GNU/Linux, macOS and FreeBSD
Cons
- No native ARM64 build
- Installation needs administrator rights
- No update for more than a year
In short: Siril is an open-source science & math tool for 64-bit PCs. Updates have slowed down. Administrators can deploy it unattended.
Screenshots
Is Siril safe to download?
- The file is served by free-astro.org; check that it is the publisher’s official mirror
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
C4324327EA9E8E906624272FBCE5DE8DBC1A92B52CCEB7C6D1315FEEA07431CA· Open the VirusTotal report for this hash - The link answered when we last checked it (October 22, 2026)
- The source code is public
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 3 versions ›3 versions over 1 year · about 2.5 a year
| Version | Date | Size | Files |
|---|---|---|---|
| 1.2.6Latest | January 22, 2025 | 79.6 MB | 64-bit EXE (Inno Setup) |
| 1.2.1 | January 26, 2024 | 74.3 MB | 64-bit EXE (Inno Setup) |
| 1.2.0 | November 13, 2023 | 72.5 MB | 64-bit EXE (Inno Setup) |
Install from the command line
Silent install ›winget install --id Free-Astro.Siril -echoco install siril -yscoop install extras/sirilsiril-1.2.6-setup.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART /SP-Related guide: How to use winget: install and update apps
Also for other systems
brew install sirilflatpak install flathub org.siril.SirilInformation
- Publisher
- Free-Astro
- Category
- Science & maths
- Licence
- GPL-3.0 License
- Price
- Free
- Source code
- gitlab.com
- Written in
- C and C++
- Interface languages
- multiple languages
- Content rating
- All ages
- Requires
- Windows 11 / 10
- Architecture
- 64-bit
- Installer
- EXE (Inno Setup)
- Other platforms
- GNU/Linux, macOS, FreeBSD
- Version
- 1.2.6
- Released
- January 22, 2025
- Added to the catalogue
- November 13, 2023
- Versions listed
- 3
- Updates / year
- 2.5
- Chocolatey downloads
- 1,679
- Website
- siril.org
- winget ID
- Free-Astro.Siril
- Chocolatey package
- siril
- Scoop package
- extras/siril
Ratings and reviews
No reviews yet. Be the first to rate it.
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Frequently asked questions
Is Siril free?
Yes. Siril is open-source software under the GPL-3.0 License licence.
Is Siril safe to download?
The download comes from free-astro.org; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install Siril with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Can Siril be installed silently?
Yes. The silent install page lists the exact command for each installer.
Does Siril run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 64-bit version through emulation.
Where can I download an older version of Siril?
The versions page lists all 3 versions with links to their official installer files, back to November 13, 2023.
What are alternatives to Siril?
Stellarium, KiCad, Quarto, Qalculate! and JASP. The alternatives page compares them.
