In the last few months, I have been searching for online Gujarati ebooks, here are few sites I have come across where you can read/access Gujarati ebooks (mostly scanned) on the internet legally.
Gandhi Heritage Portal: https://www.gandhiheritageportal.org/
Gandhi Heritage Portal has more than 1000 Gujarati books including digitized books from MJ Library and others under Collective Commons licence.
National Digital Library of India: https://ndl.iitkgp.ac.in/
NDL is subscribed to http://www.worldebooklibrary.org/, hence all Gujarati books present in world ebook library is accessible from there.
Wikimedia only has ~100 PDF books, most under public domain but few on creative commons licence.
Gujlit also hosts ~50 books in web-page (HTML) format (not scanned versions).
Similar to Wikimedia, it has limited ~100 books, few in PDF format while others can be read on the website (No redistribution allowed).
e-Shabda is an e-shop for Gujarati books by Cygnet infotech but also hosts approximately 400+ free books.
Ektara Foundation: https://www.ekatrafoundation.org/books/ebook/ebook
This has very limited ~100 books, most of them may already be available on above-mentioned websites.
Gujarati Matrubharti: https://gujarati.matrubharti.com/
Formerly “Gujarati Pride Gujarati eBooks”, is now integrated with Matrubharti.
Please do let me know if there are any other legal sources out there other than these. I haven’t added archive.org, for in theory, it can potentially have copyrighted material uploaded by random user.