Accessible via Hein Online, Multinational Sources Compared: A Subject & Jurisdiction Index, directs researchers to sources that compare multiple jurisdictions on focused subjects.
Quality varies but there are a number of free, online, general purpose translators, e.g.:
While not a silver bullet, accuracy can be enhanced by running passages/files through multiple translators & comparing results.
Unfortunately, there is no free, online translator that's generally accepted to be good for legal terminology.