sanoTTS

sano (सानो) — Nepali for "small." A family of tiny neural text-to-speech voices — 294k to 2.27M parameters — that run with no cloud and no NPU: real-time on a ~$3 ESP32-S3 (out a GPIO into an LM386 and a speaker), or live in the browser via WASM.

Live demo: tts.ampixa.com/sanoTTS — every voice synthesizes your text live in the browser, no server, no upload.

Download

Both packages stream their weights from this repo by default.

import sanotts
sanotts.synthesize("Hello world", voice="heart")     # downloads heart/ from here

import { SanoTTS } from 'sanotts-web';               // fetches web/voices/ from here
const tts = await SanoTTS.load();
const result = await tts.synthesize('Hello world', { voice: 'heart' });

Python needs sanotts >= 0.3.0, the browser sanotts-web >= 0.3.0. Both fall back to the GitHub releases or the Pages host if Hugging Face cannot be reached, so an outage here cannot break an install. Python packages land in ~/.cache/sanotts/; set SANOTTS_VOICE_SOURCE=hf or =github to pin one host. In the browser, passing voiceBase yourself turns the fallback off, so a self-hosted deployment never quietly reaches back to our servers.

Samples

Two clips per voice are in this repo's samples/ folder; one is embedded below. "Package here" means this repo carries that voice's weights. The three languages without one currently ship only through the browser demo and the GitHub repo's web/voices/ — their packages haven't been exported yet.

SCOREQ is a no-reference naturalness predictor, higher is better; it is only reported for the English voices, which share one 24-sentence eval set. The other languages haven't been scored against a comparable reference yet.

Size does not order this table, and we are not going to pretend it does. amy at 1.46M scores higher than heart at 2.27M because they come from different teachers and different architectures, not because one is bigger. amy and the voices above it are the piperlite lineage, distilled from a Piper/VITS teacher at 22.05 kHz. heart and heart-nano are the newer nano lineage — 24 kHz, mel-100 → ConvNeXt1D → iSTFT, distilled from a Kokoro teacher through a frozen Vocos — which is the one that quantizes to int8 and runs on a microcontroller. The two are not interchangeable and the sanotts package picks the right runtime for you.

The heart and heart-nano scores were re-measured on 2026-09-04; the eval set, checkpoint hashes, exact commands and all 24 per-clip scores are in evidence/heart-diverse24-remeasure-20260904.json. They were scored on the float32 reference render. The shipped heart-nano int8 export tracks that render at 0.981 waveform correlation, and heart ships as float32 because its int8 export reached only 0.951 against a 0.98 gate.

The "robot" row is the 567,008-parameter model that runs on the ESP32-S3.

Install & use

Pip voices: heart, hfc, amy-1p8m, amy, kristin, vi, id, amy-1p1m, heart-nano. Pure numpy infer