WordByWord is a language learning platform that helps you build vocabulary naturally while reading real content. The Chrome extension highlights the words you haven't learned yet on websites, YouTube subtitles, and PDFs, allowing you to translate and save them with a single click.

Every saved word is synchronized with your personal vocabulary on WordByWord.io, where you can organize collections, review flashcards, practice with multiple learning modes, and use smart spaced repetition to remember words long-term.

Unlike traditional language learning apps, WordByWord lets you learn from the content you already enjoy instead of predefined lessons. Read articles, watch videos, study PDFs, and grow your vocabulary naturally in more than 50 languages.

Key features

• Highlight unknown words while reading

• Translate and save words instantly

• Learn from websites, YouTube, and PDFs

• Personal vocabulary with collections

• Flashcards and multiple training modes

• Smart spaced repetition

• Progress tracking

• Import & export vocabulary (CSV, PDF)

• Available in 50+ languages