Riddi – Local Text-to-Speech Browser Reader

A Chrome extension that converts web articles to speech using built-in local AI models. No cloud services, no API keys – everything runs directly in your browser, fast and secure.

👉 Download from Chrome Web Store

What is Riddi?

Riddi extracts readable content from web pages and synthesizes natural-sounding speech using bundled ONNX neural TTS models. It's perfect for:

• Listening to articles while doing other tasks
• Accessibility – have any web content read aloud
• Learning – listen to educational content hands-free
• Reducing eye strain – give your eyes a break

Features

Local AI Processing

• Runs entirely in your browser using ONNX Runtime (WebGPU with WASM fallback)
• No data sent to external servers
• Works offline once loaded

Smart Content Extraction

• Automatically detects and extracts article content using Readability.js
• Filters out navigation, ads, and other non-content elements
• Text Selection Mode – manually select specific text blocks to read

Real-time Highlighting

• Highlights the current paragraph being read
• Word-by-word highlighting synced with speech
• Smooth auto-scroll to keep content in view

Multilingual Speech

• Uses Supertonic 3 with local support for 31 languages
• Detects article language automatically from page metadata and extracted text
• Manual language override is available in the popup
• 10 built-in voice styles (5 male, 5 female)
• Adjustable speech speed (0.5x – 2x)
• Quality/speed tradeoff via denoising steps

Floating Widget

• Unobtrusive player that stays in the corner
• Expand for playback controls
• Can be disabled in settings (use pop-up instead)

How to Use

Basic Playback

1. Navigate to any article or web page
2. Click the Riddi widget (bottom-right corner) to expand controls
3. Press ▶ Play to start reading the entire article
4. Use ⏸ Pause and ⏹ Stop as needed

Text Selection Mode

1. Click the ⌖ button (or press Ctrl+Shift+S) to enter selection mode
2. Hover over text blocks – they highlight with an orange outline
3. Click to select – TTS starts automatically with that content
4. Press Escape to cancel selection mode

Settings (Popup)

Click the Riddi icon in the Chrome toolbar to access:

• Voice – Choose between M1-5, F1-5
• Language – Auto-detect from the page or choose a specific language
• Speed – Adjust playback rate
• Quality Steps – Higher = better quality, slower generation
• Widget Toggle – Show/hide the floating widget

Keyboard Shortcuts

Local Development

Prerequisites

• Git LFS
• Node.js 22+
• npm or pnpm

Setup

#If you don't have Git LFS installed
#mac
brew install git-lfs
#linux
sudo apt-get install git-lfs
#windows
git lfs install

# Clone the repository
git clone https://github.com/pmbstyle/Riddi.git
cd riddi

# Install dependencies
npm install

# Build the extension
npm run build

Load in Chrome

1. Open chrome://extensions/
2. Enable Developer mode (top-right toggle)
3. Click Load unpacked
4. Select the dist folder

Development Mode

# Watch mode with hot reload
npm run dev

After making changes, click the refresh icon on the extension card in chrome://extensions/.

Project Structure

src/
├── background/       # Service worker
├── content/          # Content script (widget, highlighting)
├── popup/            # Extension popup (Vue)
├── offscreen/        # ONNX TTS pipeline
├── lib/tts/          # TTS synthesis logic
└── shared/           # Shared types and messages

public/assets/
├── onnx/             # Neural TTS models
└── voice_styles/     # Voice embedding files

Tech Stack

• Vite + CRXJS – Extension bundling
• Vue 3 – Popup UI
• ONNX Runtime Web – Neural network inference
• Supertonic 3 – Lightweight multilingual TTS model
• Readability.js – Content extraction

Notes

• TTS models are bundled under public/assets/onnx/
• First synthesis may take a few seconds while models load
• WebGPU provides the best performance; falls back to WASM if unavailable
• Works best on article-style pages with a clear content structure