On this note I really recommend cyberchef[1]: a large collection of open-source web based utils and converters that can be chained together.
Oh and it's maintained by the GCHQ, the agency that cracked the german enigma codes.<p>[1] <a href="https://gchq.github.io/CyberChef/" rel="nofollow">https://gchq.github.io/CyberChef/</a>
Isn't CyberChef[0] also local and without ads, and also open source?<p>[0] <a href="https://gchq.github.io/CyberChef/" rel="nofollow">https://gchq.github.io/CyberChef/</a>
love this, i always use sketchy websites for simple utils like counting number of words, validating JSON etc.<p>though this is nothing that can't be done on the CLI (wc, jq, grep etc) - it's obviously easier through a web interface if it's only used sparingly.