Document Converter for batch conversion

Many file types are convertible to PDF, but usually via the application that created that file type, and whether it offers a PDF export feature to perform the translation. This will produce the most accurate PDF to the original content.

HTML by itself is rather bland and it is the CSS3 styling (or JavaScript) that transforms a PDF into what is seen in a browser. Different browsers may render the same HTML/CSS3/JavaScript content differently and Brave, Chrome, Firefox and Safari have different rendering engines to transform what you see in the browser to PDF. Once again, there is no magic conversion tool to do this correctly that is standalone from a browser. The free wkhtml2pdf utility won't do as good a job as the browser though.

Apple's Shortcuts offers a Make PDF action that according to its description, can take any input to output a PDF, but if you provided it with HTML/CSS3/JavaScript file, it would be a PDF of that syntax, not as it would appear in a browser.

The free Pandoc can perform document conversions and even to PDF, but it has prerequisites for this capability and the resulting PDF may not appear as would the exported original document in its relevant application.

You need to share the original document type and the intended converted document type here. Usually, if the from/to conversion formats are supported and an application can be scripted, it involves either an Automator or Shortcuts custom solution to batch process the files. For some applications, this may require AppleScript support by the application vendor.

It will likely be in the /usr/local/bin location and you won't find it unless you have /user/local/bin first in your PATH statement in your Shell dotfile, or you explicitly type /usr/local/pandoc. There is also a /usr/local/man/share/man1/pandoc.1 manual page installed.

Again… what document type is to be converted to a resulting document type? That is key to gaining an answer here. There is no generic document converter that is garbage in and garbage out.

Pandoc has a macOS installer that you can download. One for Intel (X86_64) and one for Apple Silicon (arm64). Nothing scary about a standard macOS installer.