The [new-ish at the time of writing in 2017] Fetch API is intended to make GET requests easy, but it is able to POST as well.
let data = {element: "barium"};
fetch("/post/data/here", {
method: "POST",
body: JSON.stringify(data)
}).then(res => {
console.log("Request complete! response:", res);
});
If you are as lazy as me (or just prefer a shortcut/helper):
window.post = function(url, data) {
return fetch(url, {method: "POST", body: JSON.stringify(data)});
}
// ...
post("post/data/here", {element: "osmium"});