Multi Converter is a site made to showcase the JS library "multi-unit-converter" made to converter all occurences of units in a text to specified units as all other libraries are just a one to one conversion of a number and unit but this is meant to handle cases such recipes, equations and etc that could contain multiple units that you are unfimiliar with so would like to convert them all at once instead of doing it one by one.
Just select your prefered units from the lists on the left or select a template from the ones available, and the precision (significant figures) you want to round to, then paste the text you wish to convert in the input box and it will automatically convert the units and output them in the output box.
The library uses RegEx to detect all possible spellings of units that occur after a number, resolves the aliases of the units into their actual symbol, then converts the numbers using switch statements, rounds to them to the selected precision, the finally replaces them in the actual text.
If you want the code for yourself, report a bug or suggest an improvment, check out the links in the navbar of the website.