rjson

The jsonlite package exists to address exactly this problem: “A practical and consistent mapping between JSON data and R objects.” Its toJSON function provides this desired result with the default options: library(jsonlite) x <- toJSON(res1) cat(x) ## [{“id”:1,”value”:”server1″},{“id”:2,”value”:”server2″}, ## {“id”:3,”value”:”server3″},{“id”:4,”value”:”server4″}, ## {“id”:5,”value”:”server5″}]