Comparing download times of base R and the curl package: url <- 'https://jeroen.github.io/data/nycflights13.json' tmp <- tempfile() system.time(download.file(url, tmp, quiet = F) system.time(curl::curl_download(url, tmp, quiet = F)) Because this is an uncompressed file, the gzipped download is about 7x faster. For the solution see https://curl.se/libcurl/c/CURLOPT_ACCEPT_ENCODING.html :
To aid applications not having to bother about what specific algorithms this particular libcurl build supports, libcurl allows a zero-length string to be set ("") to ask for an Accept-Encoding: header to be used that contains all built-in supported encodings.