How to create image to pdf converter app using flutter full code

Below is a complete, working Flutter example of an Image → PDF Converter app.

The app will:

• Pick images from gallery
• Convert them into a single PDF
• Save the PDF to device storage

This is a beginner-friendly but production-ready structure.

1️⃣ Create Flutter Project

flutter create image_to_pdf
cd image_to_pdf

2️⃣ Add Dependencies (pubspec.yaml)

dependencies:
  flutter:
    sdk: flutter
  image_picker: ^1.0.7
  pdf: ^3.10.7
  path_provider: ^2.1.2
  permission_handler: ^11.3.0

Run:

flutter pub get

3️⃣ Android Permissions

android/app/src/main/AndroidManifest.xml

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

For Android 13+, also add:

<uses-permission android:name="android.permission.READ_MEDIA_IMAGES"/>

4️⃣ Full Flutter Code (lib/main.dart)

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Image to PDF',
      home: ImageToPdfPage(),
    );
  }
}

class ImageToPdfPage extends StatefulWidget {
  @override
  State<ImageToPdfPage> createState() => _ImageToPdfPageState();
}

class _ImageToPdfPageState extends State<ImageToPdfPage> {
  final ImagePicker _picker = ImagePicker();
  List<File> images = [];

  Future<void> pickImages() async {
    final pickedFiles = await _picker.pickMultiImage();
    if (pickedFiles.isNotEmpty) {
      setState(() {
        images = pickedFiles.map((e) => File(e.path)).toList();
      });
    }
  }

  Future<void> createPdf() async {
    await Permission.storage.request();

    final pdf = pw.Document();

    for (var img in images) {
      final image = pw.MemoryImage(img.readAsBytesSync());
      pdf.addPage(
        pw.Page(
          build: (pw.Context context) {
            return pw.Center(child: pw.Image(image));
          },
        ),
      );
    }

    final dir = await getExternalStorageDirectory();
    final file = File("${dir!.path}/images_to_pdf.pdf");

    await file.writeAsBytes(await pdf.save());

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text("PDF saved at ${file.path}")),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("Image to PDF Converter")),
      body: Column(
        children: [
          ElevatedButton(
            onPressed: pickImages,
            child: const Text("Pick Images"),
          ),
          Expanded(
            child: GridView.builder(
              itemCount: images.length,
              gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 3,
              ),
              itemBuilder: (context, index) {
                return Image.file(images[index], fit: BoxFit.cover);
              },
            ),
          ),
          if (images.isNotEmpty)
            ElevatedButton(
              onPressed: createPdf,
              child: const Text("Convert to PDF"),
            ),
        ],
      ),
    );
  }
}

5️⃣ App Features

✅ Select multiple images
✅ Convert images to single PDF
✅ Save PDF to storage
✅ Works offline

6️⃣ Output Location

On Android, PDF will be saved in:

/Android/data/<your.package.name>/files/images_to_pdf.pdf