transpile vs. compile

What does it mean when we say that babel is a transpiler?

According to Shawn Wang (known on the internet as swxy), when babel transpiles, it “compile[s] from Javascript to Javascript”.¹

So, if we’re comparing transpiling to compiling - the former is from it’s language to itself (at a target specified by the developer to be compatible with the consuming application — in this case the various browsers) while the latter is taking a language and transforming it into a different language - whether it’s a lower level language (C or C++) or machine code.

Update According to this article on ReScript, the above definition is not quite right. Instead a transpiler is a compiler which targets another language (any language) while a compiler targets bytecode. Considering the Elm compiler (which is the project’s name, not transpiler) targets Javascript, I’m still inclined believe Shawn.

Footnotes

• ¹ This comes from Shawn’s interesting blog The Many jobs of JS Build Tools: For new JS Developers