Google Sheets is the best online option.
Google Sheets
Offers functions and a design similar to Excel.
Work is saved to the cloud.

Includes helpful and free-to-use templates.
Google’s lack of privacy.
Its cloud-first design means taking extra steps to keep local copies of content.

It also works through a mobile app.
Sheets works like any other spreadsheet.
WPS Office Spreadsheet
Works on all the popular desktop and mobile platforms.

Unique features like a batch file renamer and a thesaurus.
Only the paid version has a full suite of features.
Must download the full suite.

Several prompts to upgrade.
WPS Officeis a suite like MS Office that includes a program called Spreadsheet.
Its beautiful, intuitive interface is simple to use, and it supports lots of awesome features.

you could open these common file types and save to them.
This software supports more than a hundred formulas for working with data.
OpenOffice Calc
Works with most spreadsheet file formats.

Extra extensions and templates are available.
The Help section isn’t very extensive.
An overly simplistic interface.
Spread32
Hundreds of functions.
Stores a lot of data.
Only available for Windows.
Doesn’t open Excel files.
Like all these spreadsheet programs, Spread32 supports hundreds of functions and all the regular formatting tools.
The program interface is easy to use and provides a clean working space.
Spread32 is portable, which means you don’t have to install it to use it.
Also, it can run from portable media like a flash drive.
Gnumeric
Simple and easy to use interface.
Doesn’t include all the functions available in Excel.
Graphs and charts lack style.
Designed for Linux only.
Gnumeric is an advanced spreadsheet program.
There are numerous tools you won’t find in some of the other software from this list.
Windows binaries aren’t available, so this is only useful for Linux users.
SSuite Accel
Has an effective formula search utility.
It’s easy to connect data sources.
Installs extra utilities automatically.
Supports limited file formats.
Files save to formats like XLS and CSV, but also to some Accel-specific ones like VTS and ATP.
SSuite Accel connects to external database files and supports opening files directly from Dropbox and otheronline storage services.