KiCAD, Fusion 360, Altium Designer, etc-

1. https://www.ultralibrarian.com/
2. https://www.samacsys.com/
3. https://www.we-online.com/en
4. https://componentsearchengine.com/
5. https://snapeda.com/
6. https://www.snapeda.com/home/
7. https://www.analog.com/en/index.html
8. https://easyeda.com/components