Viewing PDF files in Flutter

This article walks you through a couple of examples of viewing PDF (.pdf) documents from within a Flutter app. We are going to use the following PDF file for testing purposes:

https://www.kindacode.com/wp-content/uploads/2021/07/test.pdf

Using advance_pdf_viewer plugin

This package helps you view both local and network pdf files with ease. You can install it by executing the following command:

flutter pub add advance_pdf_viewer

Example Preview

The beautiful control bar in the demo video above was added automatically by the plugin.

The Complete Code

// main.dart
import 'package:flutter/material.dart';
import 'package:advance_pdf_viewer/advance_pdf_viewer.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        // Remove the debug banner
        debugShowCheckedModeBanner: false,
        title: 'Kindacode.com',
        theme: ThemeData(
          primarySwatch: Colors.indigo,
        ),
        home: const HomePage());
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  bool _isLoading = true;
  late PDFDocument _pdf;

  void _loadFile() async {
    // Load the pdf file from the internet
    _pdf = await PDFDocument.fromURL(
        'https://www.kindacode.com/wp-content/uploads/2021/07/test.pdf');

    setState(() {
      _isLoading = false;
    });
  }

  @override
  void initState() {
    super.initState();
    _loadFile();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Kindacode.com'),
      ),
      body: Center(
          child: _isLoading
              ? const Center(child: CircularProgressIndicator())
              : PDFViewer(document: _pdf)),
    );
  }
}

If you want to render an offline PDF document from your assets folder, use this:

 _pdf = await PDFDocument.fromAsset('assets/test.pdf'); // Replace test.pdf with your own file name

In this case, don’t forget to add an asset section in your pubspec.yaml file:

flutter:
  uses-material-design: true

  assets:
    - assets/

Using url_launcher plugin

This plugin will open the PDF file with the default web browser of the device.

Installation

flutter pub add url_launcher

Add required permissions

For iOS, add the following to your ios/Runner/Info.plist file:

<key>LSApplicationQueriesSchemes</key>
<array>
  <string>https</string>
</array>

For Android, modify your AndroidManifest.xml file:

<queries>
  <intent>
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="https" />
  </intent>
</queries>

Screenshot:

Example Preview

The Complete Code

// main.dart
import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher_string.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        // Remove the debug banner
        debugShowCheckedModeBanner: false,
        title: 'Kindacode.com',
        theme: ThemeData(
          primarySwatch: Colors.indigo,
        ),
        home: const HomePage());
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  void _viewFile() async {
    const url = 'https://www.kindacode.com/wp-content/uploads/2021/07/test.pdf';

    try {
      await launchUrlString(url);
    } catch (err) {
      debugPrint('Something went wrong');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Kindacode.com'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: _viewFile,
          child: const Text('View PDF'),
        ),
      ),
    );
  }
}

Conclusion

We’ve gone over a few examples of reading PDF files from within an app. If you are working with other file types, take a look at the following tutorials:

• Flutter: Load and display content from CSV files
• Flutter: How to Read and Write Text Files
• How to encode/decode JSON in Flutter
• How to read data from local JSON files in Flutter

If you’d like to explore more new and interesting stuff in Flutter:

• Using GetX (Get) for Navigation and Routing in Flutter
• Using GetX (Get) for State Management in Flutter
• Flutter StreamBuilder examples (null safety)
• Flutter FutureBuilder example (null safety)

You can also check out our Flutter category page, or Dart category page for the latest tutorials and examples.