FileReader compatibility use and performance

The FileReader object lets web applications asynchronously read the contents of files (or raw data buffers) stored on the user's computer.

There are different approaches of reading files in order to upload them.

I came across a problem when trying to read large files. In my case these files where APK and IPA files (Android and IOS mobile applications)

I found a specific problem that actually reading very large files (over 160MB), was not possible to Firefox.

I found that the problem was generated with the following code line:

var fr = new FileReader();

fr.readAsDataURL(application);

readAsDataURL cannot finish its job and no error is provided, as well, the onload/onloadend 

function is not applied.

The solution was replacing the readAsDataURL by the readAsArrayBuffer.

I also found that the reading is performed much faster with the readAsArrayBuffer. Specially for

large files.

Both methods are compatible with all new browsers http://caniuse.com/#feat=filereader

Files: 

Small file: ipa, len: 5.5M

Large file: ipa, len: 158M

 
 
 
 
 
 


  
Browser   
  
      readAsDataURL
  

  
      readAsArrayBuffer
  

 

  

  
                  Small File
  
             Large File
  
                         Small File
  
              Large File
 

  
Edge
  
1021
  
12332
  
116
  
3034
 

  
IE 10
  
114
  
3051
  
16
  
256
 

  
Chrome
  
18
  
995
  
33
  
982
 

  
Firefox
  
345
  
5890
  
13
  
119