Hi,<p>I find myself wanting to quickly parse/decode/unescape sensitive data via randomly found sites but cannot. I wonder if there is an existing solution to making sure a random base64 encoder site will not phone home with my data.<p>Specific use cases:<p>- Parse a JWT using jwt.io<p>- Encode/unescape/parse data from a specific format (base64, protobuf, ...)<p>- Hashing a password<p>- Generating Bitcoin wallet using bitaddress.org<p>The solutions I end up doing:<p>- Finding a way to do it offline (in a terminal) or using/writing a script I can safely audit.<p>- Load up a VM, load the site, cut it from network, make use of the site and throw away the VM.<p>I am debating on creating a Browser extension to solve this problem, but wanted to get ideas from you to see if I am missing something that already exists.<p>The extension would have an isolate functionality that would:<p>- Cut off network access for a tab<p>- Cut off access to other tabs (Not sure how to do this, temporary containers in Firefox?)<p>- Listen for tab close event and clear all browser data for that site (cookies, storage, workers, history etc...)<p>What do you think?