Parsing Excel+ODS. By means of JavaScript. How?

Question

JavaScript

There is a task: to parse excel + ods files with javascript, despite the fact that a person is involved in the parsing, i.e. corrects with handles in the browser.
Have not yet decided "on the server" or "on the client", it's probably better to do both.
If possible on the client, tell me how and what to parse, maybe there are libraries, manuals?
If on the server, then we use NodeJS. Please tell me tested and working modules.
Thanks in advance for the tips.

Answer 1

Here is the best library:
https://github.com/SheetJS/js-xlsx