Piper

Piper is an open-source, local text-to-speech system developed by the Home Assistant team. It runs entirely offline and supports a wide variety of voice models in multiple languages. Piper is command-line based and designed for integration into other applications — it is used by Home Assistant, screen readers, and custom voice pipelines.

Best for: Developers and power users who need fast, scriptable TTS for automation or voice apps

• ✓ Runs fully offline
• ✓ 100+ voice models across many languages
• ✓ Very low latency — optimized for speed
• ✓ CLI interface for scripting and pipelines
• ✓ ONNX-based — runs on CPU and GPU
• ✓ Used by Home Assistant and other open-source projects