Force download of 'data:text/plain' URL

As of now, it has been made possible to use <a download> in Chrome. Using dispatchEvent, you can download any string as file (even with a custom filename) whenever you want. Here's a utility function to use it:

var downloadFile = function(filename, content) {
  var blob = new Blob([content]);
  var evt = document.createEvent("HTMLEvents");
  evt.initEvent("click");
  $("<a>", {
    download: filename,
    href: webkitURL.createObjectURL(blob)
  }).get(0).dispatchEvent(evt);
};

Usage:

downloadFile("foo.txt", "bar");

It uses jQuery and the webkit prefix, but both can be avoided.

Try this:

<a download="file_downloaded_via_data_URL.txt"
href="data:text/plain;base64,SGVsbG8sIHdvcmxkISBJJ20gZG93bmxvYWRlZCB2aWEgImRhdGE6dGV4dC9wbGFpbjsuLi4iIFVSTCB1c2luZyA8YSBkb3dubG9hZD0iZmlsZV9uYW1lIi4uLj4uDQpNeSBiaXJ0aHBsYWNlOiBodHRwOi8vc3RhY2tvdmVyZmxvdy5jb20vcXVlc3Rpb25zLzY0Njg1MTcvDQoNCk1vcmUgYWJvdXQ6DQpodHRwOi8vd3d3LnczLm9yZy9UUi9odG1sL2xpbmtzLmh0bWwjYXR0ci1oeXBlcmxpbmstZG93bmxvYWQNCmh0dHA6Ly93d3cudzMub3JnL1RSL2h0bWwvbGlua3MuaHRtbCNkb3dubG9hZGluZy1yZXNvdXJjZXMNCg0KQnJvd3NlciBzdXBwb3J0OiBodHRwOi8vY2FuaXVzZS5jb20vZG93bmxvYWQ=">
    Download text file
</a>

It uses HTML5 attribute download="filename.ext". (no JS needed:)

More about: http://www.w3.org/TR/html/links.html#downloading-resources

Browser support can be checked at http://caniuse.com/download

(As for now, 2013, no IE nor Safari support)

I think, you can make a fallback for not-supporting browsers: use JS to change value of href="..." to the URL of your server script (which will return the file contents with appropriate HTTP header Content-disposition: attachment;filename=filename.txt).

Here is a pure Javascript solution for creating a text blob and download as text file

var fileContent = 'This is sample text file';
var fileName = 'sampleFile.txt';

const blob = new Blob([fileContent], { type: 'text/plain' });
const a = document.createElement('a');
a.setAttribute('download', fileName);
a.setAttribute('href', window.URL.createObjectURL(blob));
a.click();