An abstraction to allow working with files across multiple platforms.


Import package:cross_file/cross_file.dart, instantiate a XFile using a path or byte array and use its methods and properties to access the file and its metadata.


import 'package:cross_file/cross_file.dart';

final file = XFile('assets/hello.txt');

print('File information:');
print('- Path: ${file.path}');
print('- Name: ${}');
print('- MIME type: ${file.mimeType}');

final fileContent = await file.readAsString();
print('Content of the file: ${fileContent}');  // e.g. "Moto G (4)"

You will find links to the API docs on the pub page.

Web Limitations

XFile on the web platform is backed by Blob objects and their URLs.

It seems that Safari hangs when reading Blobs larger than 4GB (your app will stop without returning any data, or throwing an exception).

This package will attempt to throw an Exception before a large file is accessed from Safari (if its size is known beforehand), so that case can be handled programmatically.

Browser compatibility

Data on Global support for Blob constructing

Data on Global support for Blob URLs


This package supports both web and native platforms. Unit tests need to be split in two separate suites (because native code cannot use dart:html, and web code cannot use dart:io).

When adding new features, it is likely that tests need to be added for both the native and web platforms.

Native tests

Tests for native platforms are located in the x_file_io_test.dart. Tests can be run with dart test.

Web tests

Tests for the web platform live in the x_file_html_test.dart. They can be run with dart test -p chrome.