Privacy Policy — Lex: Learn English with YouTube

Last updated: July 3, 2026

Lex is a Chrome extension that helps people learn English through YouTube videos. This page explains what data Lex collects and how it is used.

What we collect

• Account data: your email address, used to create and sign in to your Lex account. Passwords are stored by our authentication provider in hashed form.
• Learning content: words you click in subtitles, your messages to the AI tutor, and audio you record when using dictation or voice conversation.
• Video subtitles: the subtitle text of YouTube videos you open Lex on. When a video has no subtitles, its audio track may be transcribed instead.
• Usage records: each request to the AI models is logged with its type, time, and cost, linked to your account, so that usage can be displayed and billed.
• Settings: your preferences (models, prompts, display options), linked to your account.

How we use data

Your requests (text and audio) are sent through our server to third-party AI providers — OpenAI, Anthropic, Google, and Groq — to generate word explanations, tutor replies, voice responses, and transcriptions. We use usage records for metering and billing, and technical logs for diagnosing problems.

What we do not do

• We do not sell your data.
• We do not show ads or use your data for advertising.
• We do not collect your browsing history.

Storage

Your data is stored with our backend provider (Supabase). Voice recordings and request logs are kept to operate the service.

Deletion

You can request deletion of your account and all associated data by writing to nikolaev.gd@gmail.com.

Contact

Questions about this policy: nikolaev.gd@gmail.com