The only way I'm aware of is the trick used by FileSaver.js:
- Create a hidden
<a> tag. - Set its
href attribute to the blob's URL. - Set its
download attribute to the filename. - Click on the
<a> tag.
Here is a simplified example (jsfiddle):
var saveData = (function () { var a = document.createElement("a"); document.body.appendChild(a); a.style = "display: none"; return function (data, fileName) { var json = JSON.stringify(data), blob = new Blob([json], {type: "octet/stream"}), url = window.URL.createObjectURL(blob); a.href = url; a.download = fileName; a.click(); window.URL.revokeObjectURL(url); }; }()); var data = { x: 42, s: "hello, world", d: new Date() }, fileName = "my-download.json"; saveData(data, fileName);
I wrote this example just to illustrate the idea, in production code use FileSaver.js instead.
Notes
- Older browsers don't support the "download" attribute, since it's part of HTML5.
- Some file formats are considered insecure by the browser and the download fails. Saving JSON files with txt extension works for me.