QTranslate

The translation tool that Questsoft abandoned. Rebuilt from scratch. Built to last.

Download · Plugin Guide · Contributing · Wiki

The original QTranslate by Questsoft was the best desktop translation tool on Windows — until development stopped, APIs broke, and users were left with a dead app.

This is a full rewrite in Kotlin with one core design change: everything is a plugin. Translation engines, OCR, TTS, spell checkers, dictionaries — all separate JARs you install at runtime. When a service changes its API or shuts down, you swap the plugin. The app keeps running.

What it does

Select text anywhere → press Ctrl+Q → translation appears instantly. That's the core of it.

<div align="center"> <img src="docs/images/screenshot-quick-translate.png" alt="Quick Translate popup" width="500"> <br><sub>Quick Translate — select text in any app, press Ctrl+Q</sub> </div> <br>

For longer work: open the main window, type or paste, translate. Switch engines in one click. Run OCR on a screenshot. Listen to pronunciation. Check spelling. Browse history. All from the keyboard, all without opening a browser.

<div align="center"> <table> <tr> <td align="center" width="50%"> <img src="docs/images/screenshot-extra-output.png" alt="Extra output panel" width="340"><br> <sub><b>Extra output panel</b> — backward translation, summary, or rewrite alongside the main result</sub> </td> <td align="center" width="50%"> <img src="docs/images/screenshot-rtl.png" alt="RTL layout" width="340"><br> <sub><b>RTL support</b> — full layout mirroring for Arabic, Hebrew, Farsi</sub> </td> </tr> <tr> <td align="center" width="50%"> <img src="docs/images/screenshot-light.png" alt="Light theme" width="340"><br> <sub><b>Light theme</b> — fully themeable with FlatLaf, dark and light</sub> </td> <td align="center" width="50%"> <img src="docs/images/screenshot-plugins.png" alt="Plugin manager" width="340"><br> <sub><b>Plugin manager</b> — install, configure, enable, disable at runtime</sub> </td> </tr> </table> </div>

Features

Translation

| | | |---|---| | Quick Translate popup | Ctrl+Q on any selected text — popup with result, no main window needed | | Instant translation | Translates as you type with configurable debounce | | Inline replace | Ctrl+Shift+T — translates selected text and pastes the result back in place | | Backward translation | See the round-trip result alongside the main output — spots awkward phrasing instantly | | Summarize | Get a condensed version of long text, configurable length | | Rewrite | Rewrite in a different style: Formal, Casual, Concise, Detailed, or Simplified | | Translation history | Full undo/redo through every past translation |

Input

| | | |---|---| | Screen OCR | Draw a rectangle anywhere on screen, extract the text, translate it | | Spell checking | Live underlines as you type, click a suggestion to apply | | Remove line breaks | Strips newlines from pasted text so PDF content translates as sentences | | Language filter | Pin 3–4 target languages so the picker isn't overwhelming | | Cycle languages | Ctrl+L steps through pinned languages without touching the mouse |

Services & plugins

| | | |---|---| | Plugin system | Install .jar plugins at runtime — no restart, no reinstall | | Service presets | Save different engine combinations for different contexts | | Google Services | Translator, TTS, OCR, Spell Checker, Dictionary — included | | Bing Services | Translator, TTS, Spell Checker — included |

Interface

| | | |---|---| | Three layouts | Classic (stacked), Side-by-side, Compact (tabbed) | | Global hotkeys | Every action is bindable, configurable as global or app-local | | RTL support | Full layout mirroring for Arabic, Hebrew, Farsi, and more | | 15+ themes | Dark and light, via FlatLaf — including animated transitions | | Portable | Runs from any folder, all data lives next to the JAR |

Installation

Requires Java 11 or later — download from Adoptium if you need it.

Download QTranslate-<version>.zip from Releases
Unzip anywhere
Run QTranslate.jar

QTranslate/
  ├── QTranslate.jar                ← double-click, or: java -jar QTranslate.jar
  ├── plugins/
  │     ├── google-services-plugin.jar
  │     └── bing-services-plugin.jar
  └── languages/
        ├── en-GB.toml
        ├── ar-SA.toml
        ├── de-DE.toml
        ├── es-ES.toml
        ├── fr-FR.toml
        ├── ja-JP.toml
        ├── pt-BR.toml
        ├── ru-RU.toml
        ├── tr-TR.toml
        └── zh-CN.toml

Google and Bing plugins are included. Add your API keys in Settings → Plugins → [plugin] → Configure.

Getting "This application requires a Java Runtime Environment"? Java isn't installed or JAVA_HOME isn't set. This video covers the full process: ▶ How to Install Java JDK and Set JAVA_HOME (first 7 minutes)

Build from source → Building from Source

Quick start

Launch QTranslate.jar — it starts in the system tray
Select text anywhere on screen
Press Ctrl+Q — Quick Translate popup opens with the result ready
Press Ctrl+E — listen to the selected text
Press Ctrl+I — draw a screen region to OCR and translate

Open Settings (gear icon) to configure API keys, themes, hotkeys, and service presets.

Plugins

Installing a plugin: Settings → Plugins → Install Plugin → select .jar → Enable → Configure → assign in Services & Presets

Full guide → Installing Plugins

Community plugins

Built a plugin? Submit it here — quality plugins get listed and promoted to all QTranslate users.

| Plugin | Services | Author | |--------|----------|--------| | (be the first) | | |

Build a plugin

A minimal translator is ~50 lines of Kotlin. No framework, no registration — implement a few interfaces, build a fat JAR, install it through the UI.

class MyPlugin : Plugin<PluginSettings.None> {
    override val id      = "com.example.my-plugin"
    override val name    = "My Plugin"
    override val version = "1.0.0"

    override fun getSettings() = PluginSettings.None
    override fun getServices() = listOf(MyTranslatorService())
}

The bundled Google and Bing plugins are fully open source in plugins/ — they're the best real-world reference for auth, language mapping, error handling, and settings.

Full guide → Creating a Plugin

Translate the interface

QTranslate ships with 11 languages built in:

Arabic · Chinese · English · French · German · Japanese · Portuguese · Russian · Spanish · Turkish

Want another language? Copy languages/en.toml, rename it to your language code, translate the values. No code needed.

Guide → Adding a Language

Architecture

Clean Architecture + MVI. Nothing leaks between layers:

:api        ← plugin interfaces — plugins only depend on this
:core       ← business logic, use cases, MVI stores
:ui-swing   ← Swing UI, Renderable<State> components
:app        ← composition root
:plugins/*  ← Google, Bing, community plugins

Guide → Architecture

Contributing

Bug fixes, features, translations, docs, and plugins all welcome. Look for good first issue for well-scoped starting points.

→ Contributing Guide

MIT License

<div align="center"> <br> <sub>Built with Kotlin · FlatLaf · Ktor · Coroutines</sub> <br><br> <sub>Found it useful? A ⭐ helps other people find the project.</sub> </div>

QTranslate

Install / Use

README

QTranslate

What it does

Features

Translation

Input

Services & plugins

Interface

Installation

Quick start

Plugins

Community plugins

Build a plugin

Translate the interface

Architecture

Contributing