Privacy Policy

Last updated: September 14, 2026

Thank you for using YouMoji - On-Device AI Emojis (the "Extension"). This Privacy Policy explains how the Extension handles data when you use it. By installing and using the Extension, you agree to the practices described in this policy.

Single Purpose Statement

The single purpose of YouMoji is to parse YouTube video captions locally using an on-device AI model to display real-time floating emotion emojis on the video player.

Data Collection

Information We Do NOT Collect

YouMoji operates 100% on-device. We do not collect, store, or transmit:

• Your browsing history or visited URLs (outside of local caption stream parsing on youtube.com)
• Your watch history, search queries, or video subtitles
• Personal identifiers, IP addresses, account credentials, or cookies
• Telemetry, analytics, or usage tracking metrics

Locally Stored Data

The Extension uses Chrome's isolated local storage (chrome.storage.local) exclusively to save your local UI preferences:

• Master Switch State — Enabled / Paused status
• Confidence Threshold — Match level threshold slider value
• Floating Position — Preferred floating particle anchor zone
• Language Selection — Active interface language preference (Auto, English, Simplified Chinese, Japanese, Korean)
• Enabled Emoji Sources — Selected visual asset sets (Animated 3D, Twemoji, Fluent 2D, JoyPixels)

All stored preferences remain exclusively on your local device and are never synchronized or transmitted to any server.

Data Handling and Network Requests

No Outbound Network Requests

AI emotion inference is performed entirely on your device. The Extension does not initiate any HTTP, HTTPS, fetch, or XHR network requests during operation. Subtitle text processed by the Emo model never leaves your browser sandbox.

No Remote Code Execution

The Extension does not load, fetch, or execute any remote code or external scripts. All WebAssembly binaries (LiteRT.js), model files (`emo.tflite`), scripts, and visual assets are 100% bundled within the local extension package installed from the Chrome Web Store.

Permissions Usage

• *://www.youtube.com/* — Required to capture player caption streams and render floating emojis on YouTube watch pages.
• offscreen — Required to maintain a dedicated background WebAssembly context for LiteRT model execution without interrupting video playback.
• sidePanel — Required to display user configuration controls, threshold sliders, language selector cards, and an offline testing playground.
• storage — Required to persist user UI settings locally.

Data Sharing and Third Parties

We do not sell, rent, trade, or share any user data with advertisers, data brokers, or third parties. Because no data is collected or transmitted, no user data exists to be shared.

As required by the Chrome Web Store Developer Program Policies, we explicitly declare that user data is:

• Not sold to third parties under any circumstances
• Not used or transferred for purposes unrelated to the Extension's core single purpose
• Not used or transferred to determine creditworthiness or for lending purposes

Data Security and Control

All configuration data is stored in Chrome's isolated chrome.storage.local, which cannot be accessed by external websites or other extensions. You can clear all stored preferences at any time by resetting settings inside the Sidepanel or by uninstalling the Extension.

Changes to This Policy

If this Privacy Policy is updated, the revised policy will be posted on this page with an updated revision date.

Back to YouMoji Home | All Projects