Download attribute is NOT supported in IE and iOS Safari

IE<10:

Command SaveAs using execCommand can do the trick, by making element's contents downloadable.

Cons:

• Problems in some versions of IE running on Win7 [I don't know if it's fixed Here]
• Need a DOM element to contain data

IE>=10

Using msSaveBlob, it's a method that allows to save Blob or File by sending this headers:

Content-Length: <blob.size>
Content-Type: <blob.type>
Content-Disposition: attachment;filename=<defaultName>
X-Download-Options: noopen

Check Saving files locally using Blob and msSaveBlob

Cons:

• Need a to define a Blob

Other browsers

If you don't want to implement all that by yourself, there is a nice library FileSaver.js to save generated files on client side. It supports Firefox, Chrome, Chrome for Android, IE 10+, Opera and Safari. For IE<10 there is a fork of the library that adds saveTextAs to save text files (.htm, .html, .txt)

Cross browsers solution

A server side script that receives filename, data, meme type then send the file with the header Content-Disposition: attachment; filename=FILENAME

I think this is related to the anch.get(0).click(); not supported by all browser specially for hidden anchors, so you may try following code instead,

anch.get(0).show().focus().click().hide();

IE does not support neither navigating to a data URI nor the download attribute. You can use navigator.msSaveBlob to save file for IE 10+.
You can check window.navigator.msSaveBloband write IE specific Code otherwise use existing code to save file.
You can check following link for more details: Saving files locally using Blob and msSaveBlob

IE does not support download tag.

There's an ugly hack you can use however.

• Create an invisible iframe:

  <iframe id="dummy" style="display:none; visibility:hidden"></iframe>
  

• Write your data to the iframe's document:

  var ifd = document.getElementById('dummy').contentDocument;
  ifd.open('text/plain', 'replace');
  ifd.write('whatever you want to be in the file');
  ifd.close();
  

• Use execCommand to save the file (actually, to prompt the save as dialog):

  ifd.execCommand('SaveAs', true, 'request.bin');
  

Note that execCommand does not work in IE11. I know it is nearly impossible to detect the browser perfectly correctly. However you can try this as a backup routine if file saving fails in your code.

My javascript version for download file from IE11 with BOM and charset for excel:

$.post('/cup-frontend/requestthewholelist',
    {ipAddressList: validIpAddressListAsString},   // add custom http variables
    function (returnedData) {                      // success return
        var BOM = "\uFEFF";                        // byte order mark for excel

        if (navigator.msSaveBlob) {                // ie block
            console.log("found msSaveBlob function - is't IE")
            var blobObject = new Blob([BOM + returnedData], {type: ' type: "text/csv; charset=utf-8"'});
            window.navigator.msSaveOrOpenBlob(blobObject, "cup_database.csv");
        }
        else {                                     // non-ie block
            console.log("not found msSaveBlob function - is't not IE")
            var a = window.document.createElement('a');
            a.setAttribute('href', 'data:text/plain; charset=utf-8,' + encodeURIComponent(BOM + returnedData));
            a.setAttribute('download', 'example.csv');
            a.click();
        }

    }).fail(function () {
    console.log('post error')
});

Finally, after doing hours of research I found some answer which really worked for me. Following approach worked for me.

if (navigator.msSaveBlob) { // For IE
   return navigator.msSaveBlob(blobObj, fileName);
}

In below line

navigator.msSaveBlob(blobObj, fileName)

function msSaveBlob saves the file to the disk. Parameter blobObj is the object which needs to be saved with a given name in parameter fileName

For more information please visit following link: MDN Webdocs Mozilla