Excel Worksheet Password Remover View on GitHub
Introduction
This project aims to simplify the removal of passwords on Excel's Worksheet by leaving the task of editing the XML files on an Excel document to your browser.
Security & Internal workings
In terms of security, your browser handles all the data without sending any of it to a central server like many web apps do.
This makes it, and your data, as safe as your browser can be since it is the only potential point of failure here.
As for the internal workings, the only thing this tool does is extract the content of the .xlsx file you gave it and removes the passwords on any worksheets and makes a new file with all the changes.
Once all of that is done, the file is downloaded via a data URL.
Usage
To use this tool you can either visit "aziascreations.github.io/Excel-Worksheet-Password-Remover" or download the repository and host the web page yourself.