Ctrlb

No cloud systems, data belongs only to you.
No synchronization, we work with actual files on your computer.
No ads, minimalistic design.
Any number of users.
Any number of files.
Free access for 7 days.
Works in any browser, from any tablet and phone.
The compression mode during data transfer allows you to protect your information.
When it is necessary:

There is no space on the phone, and the music collection takes up several terabytes.
You need quick access to your collection of books and notes from any device.
I want to share my collection of vacation photos with family and friends.
When you need to find the necessary information only among your books and articles.