Web/API/Blob/size

The Blob interface's size property returns the size of the Blob or File in bytes.

Syntax

var sizeInBytes = blob.size

Value

The number of bytes of data contained within the Blob (or Blob-based object, such as a File).

Example

This example uses an <input> element of type file to ask the user for a group of files, then iterates over those files outputting their names and lengths in bytes.

// fileInput is a HTMLInputElement: <input type="file" multiple id="myfileinput">
var fileInput = document.getElementById("myfileinput");

// files is a FileList object (simliar to NodeList)
var files = fileInput.files;

for (var i = 0; i < files.length; i++) {
  console.log(files[i].name + " has a size of " + files[i].size + " Bytes");
}

Specifications

Specification	Status	Comment
File APIThe definition of 'Blob.size' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`size`	Chrome Full support 5	Edge Full support 12	Firefox Full support 4	IE Full support 10	Opera Full support 11	Safari Full support 5.1	WebView Android No support No	Chrome Android Full support 18	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android Full support 1.0

Legend

Full support: Full support
No support: No support