flutter_open_chinese_convert

flutter_open_chinese_convert bridges OpenCC (開放中文轉換 / Open Chinese Convert) to your Flutter projects. You can use the package to convert between Traditional and Simplified Chinese across multiple regional standards.

Supported Platforms

Platform	Support
Android	✅ (min SDK 24 / Android 7.0)
iOS	✅
Web	✅

Installation

Add the package to your pubspec.yaml:

dependencies:
  flutter_open_chinese_convert: ^0.9.0

Then run:

flutter pub get

Conversion Options

The package supports the following conversion options:

Class	ID	Description
`S2T`	`s2t`	Simplified Chinese → Traditional Chinese
`T2S`	`t2s`	Traditional Chinese → Simplified Chinese
`S2HK`	`s2hk`	Simplified Chinese → Traditional Chinese (Hong Kong Standard)
`HK2S`	`hk2s`	Traditional Chinese (Hong Kong Standard) → Simplified Chinese
`S2TW`	`s2tw`	Simplified Chinese → Traditional Chinese (Taiwan Standard)
`TW2S`	`tw2s`	Traditional Chinese (Taiwan Standard) → Simplified Chinese
`S2TWp`	`s2twp`	Simplified Chinese → Traditional Chinese (Taiwan Standard) with Taiwanese idiom
`TW2Sp`	`tw2sp`	Traditional Chinese (Taiwan Standard) → Simplified Chinese with Mainland Chinese idiom

You can also retrieve the list of all available options at runtime:

List<ConverterOption> options = ChineseConverter.allOptions;

Usage

Call ChineseConverter.convert with the text to convert and a conversion option:

import 'package:flutter_open_chinese_convert/flutter_open_chinese_convert.dart';

var text = '鼠标里面的硅二极管坏了，导致光标分辨率降低。';
var result = await ChineseConverter.convert(text, S2TWp());
// 滑鼠裡面的矽二極體壞了，導致游標解析度降低。

Running conversion in the background

Pass inBackground: true to perform the conversion on a native background thread (Android: Kotlin coroutine on the IO dispatcher; iOS: DispatchQueue.global()). This is recommended for large text inputs to avoid blocking the UI thread:

var result = await ChineseConverter.convert(
  text,
  S2TWp(),
  inBackground: true,
);

Web: handling unsupported idiom conversion

The web implementation uses opencc-js loaded from a CDN. OpenCC-JS does not support the TW2Sp (Traditional Chinese with Mainland Chinese idiom) option. Calling convert with TW2Sp() on the web will throw an UnimplementedError by default.

To fall back to standard Traditional → Simplified conversion without idiom substitution instead of throwing an error, pass webIgnoreMissingIdioms: true:

var result = await ChineseConverter.convert(
  text,
  TW2Sp(),
  webIgnoreMissingIdioms: true, // falls back to TW2S on web
);

Web: loading the OpenCC-JS library

On the web platform, the library dynamically loads opencc-js from the jsDelivr CDN the first time convert is called. No additional setup is required, but the user's device must have internet access to reach the CDN on the first conversion call.

To use the package on the web, add the following to your web/index.html — or let the plugin load it automatically via script injection:

<!-- Optional: pre-load to avoid delay on first conversion -->
<script src="https://cdn.jsdelivr.net/npm/opencc-js@1.0.5/dist/umd/full.js"></script>

Android: 16KB page size alignment

Starting with Android 15, devices may use a 16KB memory page size. This package builds its native library (libChineseConverter.so) with the -Wl,-z,max-page-size=16384 linker flag, ensuring compatibility with Android 15+ devices without any additional configuration needed on your part.