flutter_readium

Build EPUB, PDF, audiobook, comic, and WebPub readers in Flutter with one unified Dart API—powered by Readium toolkits on iOS, Android, and Web.

Get started · Example app · API docs

iOS demo of EPUB reading preferences, synchronized read-along highlighting, and narration-driven comic panel transitions.

Captured on iOS: EPUB styling, read-along, then narrated comic panels.

Features

Read EPUB 2/3 and WebPub with pagination, scrolling, themes, and typography controls.
Open PDFs on iOS and Android, plus CBZ and DiViNa comics.
Play audiobooks with track navigation and variable speed.
Follow Media Overlay read-along highlighting and page-level narrated comic navigation.
Listen with text-to-speech, including voice, speed, and pitch controls where available.
Highlight and annotate text, search on iOS and Android, and restore reading position.
Use one Dart API for reader and playback events, with custom HTTP headers.

Select an iOS Simulator capture to see it full size.

EPUB themes	Read-along	Narrated comics

EPUB highlights	PDF pages

Quick start

Add the package:

flutter pub add flutter_readium

Pass a publication URL (for example, a file or HTTPS URL) to this reader screen:

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_readium/flutter_readium.dart';

class ReaderScreen extends StatefulWidget {
  const ReaderScreen({super.key, required this.publicationUrl});

  final String publicationUrl;

  @override
  State<ReaderScreen> createState() => _ReaderScreenState();
}

class _ReaderScreenState extends State<ReaderScreen> {
  final _readium = FlutterReadium();
  Publication? _publication;
  String? _error;

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

  Future<void> _open() async {
    try {
      final publication = await _readium.openPublication(widget.publicationUrl);
      if (!mounted) {
        await _readium.closePublication();
        return;
      }
      setState(() => _publication = publication);
    } catch (error) {
      if (mounted) setState(() => _error = error.toString());
    }
  }

  @override
  void dispose() {
    if (_publication != null) unawaited(_readium.closePublication());
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (_error != null) return Center(child: Text(_error!));
    if (_publication == null) return const Center(child: CircularProgressIndicator());
    return ReadiumReaderWidget(publication: _publication!);
  }
}

See the five-minute walkthrough for navigation, preferences, and position restoration. Complete the platform setup below before running.

Supported formats

Format	Visual	TTS	Audio	Media Overlays
EPUB 2	✓	✓	—	-
EPUB 3	✓	✓	✓	-
WebPub	✓	✓	✓	✓ (EPUB profile)
Audiobook	—	—	✓	-
PDF	✓	—	—	-
CBZ	✓	—	—	-
DiViNa	✓	—	✓¹	✓¹ (Guided Navigation)

¹ DiViNa audio narration is driven by a Guided Navigation document and synchronizes at the page level on all platforms (on Web, ts-toolkit has no DiViNa navigator, so images are rendered by a plugin-side navigator). Panel-level zoom (the segments' xywh regions) is not yet implemented on any platform.

LCP-protected publications are not currently supported. The underlying toolkits include an LCP adapter; it may be enabled in a future release.

Platform support

Feature	Android	iOS	Web
EPUB visual reading	✓	✓	✓
Comics (CBZ / DiViNa)	✓	✓	✓
PDF reading	✓	✓	—
Audiobook playback	✓	✓	✓
Media Overlays	✓	✓	✓
Text-to-Speech	✓	✓	Limited¹
Highlights / decorations	✓	✓	✓
Reader preferences	✓	✓	✓
PDF preferences	✓	✓	—
Progress saving	✓	✓	✓
Content search	✓	✓	—
Background audio	✓	✓	—

¹ Web TTS uses the browser's Web Speech API — voice availability and quality vary by browser.

macOS note: Native macOS desktop (flutter run -d macos) is not supported — a no-op stub is registered so the Flutter macOS target still compiles, but every reader call returns MethodNotImplemented. The upstream swift-toolkit is iOS-only and has marked native macOS not_planned. The iOS build runs fine on Apple Silicon Macs via "Designed for iPad".

Minimum requirements

Requirement	Version
Flutter	3.44.8+
Dart SDK	3.8.0+
Android	`minSdkVersion` 24
iOS	15.0+

Platform setup

Complete the per-platform setup below before running the reader. See the full installation guide for details.

Android

Set minSdkVersion to 24 or higher in android/app/build.gradle.

Enable core library desugaring in your app's Gradle build file. The Readium Android artifacts require it:

android {
    compileOptions {
        isCoreLibraryDesugaringEnabled = true
    }
}

dependencies {
    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.5")
}

For Groovy Gradle files, see the installation guide.

Change your MainActivity to extend FlutterFragmentActivity (not FlutterActivity) — otherwise the reader view will crash at runtime.

If using TTS or background audio, add to android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />

iOS

Add the Readium pods to your ios/Podfile. The versions must match the ones pinned in ios/flutter_readium.podspec. The example/ios/Podfile is the source-of-truth for app integration — copy these lines into your own Podfile:

source 'https://github.com/readium/podspecs'
source 'https://cdn.cocoapods.org/'

target 'Runner' do
  use_frameworks!
  use_modular_headers!

  pod 'ReadiumShared', '~> 3.11.0'
  pod 'ReadiumInternal', '~> 3.11.0'
  pod 'ReadiumStreamer', '~> 3.11.0'
  pod 'ReadiumNavigator', '~> 3.11.0'
  pod 'ReadiumOPDS', '~> 3.11.0'
end

Keep these pod versions aligned with the plugin's pin; do not override them independently.

Web

Copy the plugin's JavaScript bundle into your web app:
```
dart run flutter_readium:copy_js_file <destination_directory>
```
The destination should live inside your web/ directory.

Reference the script from web/index.html:

<script src="flutter.js" defer></script>
<script src="readiumReader.js" defer></script>

Documentation

For more detail, see the installation guide, reader walkthrough, feature guides, and API reference. For implementation details and toolkit versions, see the project README.

Example app

A complete example app is available in the repository at flutter_readium/example/, demonstrating EPUB and audiobook reading, TTS, preferences, and highlighting.

License

BSD 3-Clause — see LICENSE.