Siril is an image processing tool specially tailored for noise reduction and improving the signal/noise ratio of an image from multiple captures, as required in astronomy.
Siril can align automatically or manually, stack and enhance pictures from various file formats, even images sequences (movies and SER files).
Screenshots
Observed history
| App | Change | Version | When ↑ |
|---|
No observed changes yet.
The initial import establishes a baseline. Future version changes will appear here.
Browse the app catalogue →Upstream releases
Release notes supplied by the developer. These dates are not Flathub package publication times.
1.4.417 Jun 2026
Maintenance release for the 1.4.x series, focusing on bug fixes and stability improvements.
- Fixed several sequence-related issues, including file corruption (#1204), a crash when loading a sequence with an out-of-range reference image (#1950), and a regression when reading 16-bit FITSEQ files (#1946)
- Fixed an incorrect "not enough disk space" error on macOS external APFS/HFS volumes
- Fixed scripts in custom subfolders showing up under "Other" instead of their folder name on Windows
- The script repository search now also matches the category column
1.4.37 May 2026
Maintenance release for the 1.4.x series. This version focuses on bug fixes, stability improvements, and enhancements to the Python scripting interface.
- Fixed several crashes and critical issues (headless undo state, Python module installation failure, loading some Hubble images)
- Fixed FITSEQ handling issues, including browsing sequences with varying image sizes and individual frame reading
- Fixed multiple functional bugs (incorrect dimension constraints in sirilpy, Windows pipes naming, file extension handling in Save As dialog)
- Improved background extraction behavior and added support for None as a value for BAYERPAT
- Enhanced Python interface with new features (SirilInterface.open_dialog(), automatic script execution at startup, -async option for pyscript)
1.4.218 Feb 2026
Maintenance release for the 1.4.x series. This version focuses on bug fixes, UI improvements, Python scripting enhancements, and catalogue system optimizations.
- Fixed crash in RGB composition when aligning RGB while L is loaded but not checked
- Fixed data entry typos in Messier.csv
- Fixed crash resulting from GTK code used in command functions
- Reimplemented drag and drop and improved UI for GtkFileChooserButton
- Added local caching of index ranges from remote SPCC catalogue and improved HTTP checks
- Enabled Python methods to work with sequence frames as well as single images
- Added new Windows build environment (UCRT64) to support up to 8192 files in a sequence
- Improved robustness of Python virtual environment creation
- Enhanced GPU detection and capabilities in sirilpy.gpuhelper
- Added support for passing a list of sequence frame numbers to sirilpy.set_seq_frame_incl
1.4.15 Jan 2025
Maintenance release for the 1.4.0 series. This version focuses on build system improvements, Python scripting fixes, and catalogue system enhancements.
- Fixed build error when compiled without libgit2, libjpeg and libcurl
- Fixed issue with the tkfilebrowser submodule if duplicate filenames or bookmarks are present
- Fixed too-strict condition and off-by-one error in sirilpy
- Fixed sirilpy.FFit class data setter
- Fixed remote catalogue to avoid dependency on Gaia Archive