Shared PDFs

Most RPGs have a fillable PDF version of the character sheet. All you have to do to make that character sheet visible to your group is put it on an online PDF-sharing application, such as:

Google Sheets

Hobbiests have made character sheets using Google Sheets for various RPGs, which is a great idea because they can implement auto-calculation and can be easily shared and collaborated on.

MythWeavers

The oldest way to share character sheets on the internet, Mythweavers has character sheets for just about any RPG.

Character Sheet Online

CSO is a new simple website for creating sheets with modularity for any system, and then sharing it with your players. From their roadmap it looks like they’re trying to build it into a full VTT too.

D&D Beyond

See the section on DnDBeyond.