Full description

Online 2 PDF - online2pdf.com/remove-pdf-password
Decrypt PDF.

The site is similar to the one described above, dragging the file and saving it under a new name.
The restriction at a time is no more than 20 files (which is hardly needed) and up to 50 Mb.

I like the site described above, but sites are Are not available. So it's good to have a choice.

In addition, this site allows you to convert documents to PDF and vice versa.