other
0.025B parameters
Commercial OK
Reviewed May 2026

Piper

VITS-based neural TTS optimized for Raspberry Pi-class hardware. Ships as ONNX checkpoints with ~100 voices across 30+ languages. Powers Home Assistant's local voice stack and is the de facto open TTS for embedded devices.

License: mit·Context: 0 tokens
BLK · VERDICT

Our verdict

OP · Fredoline Eruo|VERIFIED MAY 29, 2026
unrated

Not the prettiest voice, but unbeaten on footprint and language breadth at the edge. If it runs on a Pi and needs to speak, it should probably be Piper.

Overview

VITS-based neural TTS optimized for Raspberry Pi-class hardware. Ships as ONNX checkpoints with ~100 voices across 30+ languages. Powers Home Assistant's local voice stack and is the de facto open TTS for embedded devices.

Strengths

  • Runs realtime on Raspberry Pi 4 / Pi Zero 2 — true edge deployment
  • 100+ voices across 30+ languages, all MIT-licensed
  • Pure ONNX runtime — trivial to embed in C/C++/Rust/Python apps
  • Battle-tested in Home Assistant and offline accessibility deployments

Weaknesses

  • Per-voice models are small VITS networks — quality lags Kokoro/XTTS noticeably
  • No voice cloning; voices are baked at training time
  • Limited prosody and emotion control
  • Robotic-sounding on long sentences and complex punctuation

Quantization variants

Each quantization trades model quality for file size and VRAM. Q4_K_M is the most popular starting point.

QuantizationFile sizeVRAM required
Q4_K_M0.0 GB1 GB

Get the model

HuggingFace

Original weights

huggingface.co/rhasspy/piper-voices

Source repository — direct quantization required.

Hardware that runs this

Cards with enough VRAM for at least one quantization of Piper.

Compare alternatives

Models worth comparing

Same parameter band, plus what's one tier above and below — so you can decide what actually fits your hardware.

Step down
Smaller — faster, runs on weaker hardware
No verdicted models in the next tier down yet.

Frequently asked

What's the minimum VRAM to run Piper?

1GB of VRAM is enough to run Piper at the Q4_K_M quantization (file size 0.0 GB). Higher-quality quantizations need more.

Can I use Piper commercially?

Yes — Piper ships under the mit, which permits commercial use. Always read the license text before deployment.

What's the context length of Piper?

Piper supports a context window of 0 tokens (about 0K).

Source: huggingface.co/rhasspy/piper-voices

Reviewed by RunLocalAI Editorial. See our editorial policy for how we research and verify model claims.

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Before you buy

Verify Piper runs on your specific hardware before committing money.