A privacy-first, deeply customizable open-source keyboard for Android.
What you type stays on your device. Always.

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🛡️ Privacy is the architecture, not a checkbox

Your keyboard sees everything — passwords, messages, searches. Most keyboards phone home. SonderKey can't:

Variant	Network access	Best for
🔒 Offline	❌ Impossible — no INTERNET permission in the manifest	Maximum privacy
🪶 Offline Lite	❌ Impossible	Minimal footprint, no AI
🌐 Standard	Opt-in only, with your own API keys	AI features, dynamic downloads

No tracking. No analytics. No accounts. No data collection of any kind.

✨ Features

• 🎙️ On-device voice typing — speech to text that runs entirely on your phone. Audio is never written to storage and never sent anywhere. Optional download, English.
• 🎨 Deep customization — the Sonder theme sets keys, function keys, accent and background independently, with presets, sliders, hex entry and a live preview. Plus the full color editor, key styles, adjustable layouts, custom toolbar and image backgrounds.
• 🧠 Optional AI assistance — proofread & translate with Gemini (default), Groq, or any OpenAI-compatible provider, using your key — never on by default
• 👆 Gesture typing — fast swipe input powered by a native engine
• 📋 Clipboard history — with search, pinning, and undo
• 📝 Text expander — shortcuts with dynamic date/time/clipboard variables
• 🪟 Floating keyboard — draggable, resizable, multitask-friendly
• ✍️ Handwriting input & 🔎 emoji search & 🧭 dedicated text-editing mode
• 😀 Current emoji on any Android version — a colour emoji font ships with the app, so the newest emoji appear without waiting for a system update
• 🌍 Extensive language support inherited from the HeliBoard lineage

Full documentation: docs/FEATURES.md

🗺️ Where SonderKey is going

Shipped in 2.4.0

• ✅ Offline voice typing — on-device speech recognition, built on sherpa-onnx with NVIDIA's Parakeet. Your voice never leaves your phone, which mainstream keyboards structurally cannot offer.
• ✅ Sonder theme — four independently set colours driving both the keyboard and the settings app, derived on a perceptual curve so any hue stays balanced.
• ✅ Emoji independence — the emoji set no longer depends on the age of your device's system font.

Next

1. 🌍 More voice languages — the model registry takes one entry per model; a multilingual option is the obvious next step
2. 🎨 Theme sharing — presets gallery and shareable .sonderkey theme files
3. 🔍 Privacy dashboard — see exactly which permissions are active and prove to yourself that nothing leaves the device

Follow the releases to watch it happen.

📥 Download

Grab the latest APK from Releases. Development builds are available from GitHub Actions artifacts.

🛠️ Building

./gradlew assembleStandardfullDebug   # everything, the usual build
./gradlew assembleStandardDebug       # standard variant
./gradlew assembleOfflineDebug        # no INTERNET permission at all

Requires JDK 17, Android SDK platform 36, build-tools 36.0.0 and NDK 28.0.13004108.

The SDK path must not contain spaces — the NDK's make-based toolchain fails on them.

📜 License & credits

SonderKey is licensed under GPL-3.0-only (with Apache-2.0 and CC-BY-SA-4.0 components — see the LICENSE files).

Built on the shoulders of:

• LeanType by LeanBitLab
• HeliBoard by Helium314 and contributors
• OpenBoard and the AOSP LatinIME project

All original copyright notices are preserved.

_{Made with care by Verisonder}