Open-source licences
Sunflower is built with these open-source projects. Thank you to everyone who makes them. The same list is in the app under About Sunflower in the tray menu.
| Component | What Sunflower uses it for | Licence |
|---|---|---|
| Qt for Python (PySide6) | Windows, menus and drawing | LGPL-3.0 |
| pypdfium2 with PDFium | Showing PDF pages, PDF to pictures, text | Apache-2.0 / BSD-3-Clause |
| pikepdf with qpdf | Editing, merging, protecting and compressing PDFs | MPL-2.0 / Apache-2.0 |
| ReportLab | Writing text and pages in PDFs | BSD |
| pdfplumber with pdfminer.six | Reading PDF layout for PDF to Word | MIT |
| Pillow | Pictures | MIT-CMU |
| pillow-heif | HEIC and AVIF pictures | BSD-3-Clause |
| OpenCV | Finding and straightening pages (Scan fix) | Apache-2.0 |
| ONNX Runtime | Running the background-removal model | MIT |
| Silueta model via rembg, based on U²-Net | Cut out | MIT / Apache-2.0 |
| python-docx | Word files | MIT |
| NumPy | Image maths | BSD-3-Clause |
Qt (LGPL-3.0)
Sunflower uses Qt as separate library files under the GNU Lesser General Public License, version 3. You may replace those files with your own build of Qt. Qt's source code is available from download.qt.io.
DragShift (MIT)
Sunflower began from DragShift, which is published under the MIT licence:
MIT License Copyright (c) 2026 DragShift contributors Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Questions about licences: support@sunflower-fileswap.com