How to upload multiple files with JavaScript and PHP

Adding multiple file elements for uploading multiple files is time-consuming and you need to write some extra code for this.

You can do it with a single file element by enabling multiple file selection.

Read the selected files and append in the FormData object for passing to the AJAX file for upload.

In this tutorial, I show how you can upload multiple files with JavaScript and PHP.

Contents

1. HTML
2. PHP
3. JavaScript
4. Output
5. Conclusion

1. HTML

Create a file and button element. To enable multiple file selection add multiple attribute in the file element.

Added onclick event on the button which calls uploadFile() function.

Completed Code

<div >
  <input type="file" name="files" id="files" multiple>
  <input type="button" id="btn_uploadfile" 
     value="Upload" 
     onclick="uploadFile();" >
</div>

2. PHP

Create an ajaxfile.php file and an uploads folder to store files.

Count total files and assign to $countfiles. Assign upload location to $upload_location.

Create count variable to store the number of files successfully uploaded.

Loop on the files. Read the file name and create a file path.

Read file extension and assign valid file extensions to $valid_ext Array.

If file extension exists in the $valid_ext Array then upload the file and increment $count by 1.

Return $count.

Completed Code

<?php

// Count total files
$countfiles = count($_FILES['files']['name']);

// Upload directory
$upload_location = "uploads/";

$count = 0;
for($i=0;$i < $countfiles;$i++){

   // File name
   $filename = $_FILES['files']['name'][$i];

   // File path
   $path = $upload_location.$filename;

   // file extension
   $file_extension = pathinfo($path, PATHINFO_EXTENSION);
   $file_extension = strtolower($file_extension);

   // Valid file extensions
   $valid_ext = array("pdf","doc","docx","jpg","png","jpeg");

   // Check extension
   if(in_array($file_extension,$valid_ext)){

      // Upload file
      if(move_uploaded_file($_FILES['files']['tmp_name'][$i],$path)){
        $count += 1;
      } 
   }

}

echo $count;
exit;

3. JavaScript

Create uploadFile() function which calls on button click.

Assign the total number of selected files in totalfiles variable. If totalfiles is not greater than 0 than alert("Please select a file");.

If totalfiles > 0 then create FormData object and loop on the selected files and append in the FormData object.

To send AJAX request create an object of XMLHttpRequest. With open() method set request method to "POST" and AJAX file path.

Handle AJAX successful callback with onreadystatechange() method. Assign this.responseText to response variable and alert the response.

Pass formData object with send() method.

Completed Code

// Upload file
function uploadFile() {

  var totalfiles = document.getElementById('files').files.length;

  if(totalfiles > 0 ){

    var formData = new FormData();

    // Read selected files
    for (var index = 0; index < totalfiles; index++) {
      formData.append("files[]", document.getElementById('files').files[index]);
    }

    var xhttp = new XMLHttpRequest();

    // Set POST method and ajax file path
    xhttp.open("POST", "ajaxfile.php", true);

    // call on request changes state
    xhttp.onreadystatechange = function() {
       if (this.readyState == 4 && this.status == 200) {

          var response = this.responseText;

          alert(response + " File uploaded.");

       }
    };

    // Send request with data
    xhttp.send(formData);

  }else{
    alert("Please select a file");
  }

}

4. Output

5. Conclusion

Loop on the selected files and append it to the FormData object to send multiple files for upload.