Download a File from a URL

This post shows how you can download a file in Go from a URL. We use the std lib (standard library) http.Get() [docs] and io.Copy() [docs] functions to help us with this. This function should be efficient as it will stream the data into the file, as opposed to downloading it all into memory, then to file. The file will be saved in the same directory as your program. We also show an alternative below if you want to take the filename from the URL.