WordByWord - 2026 Pricing, Features, Reviews & Alternatives

WordByWord is a language-learning platform and Chrome extension that helps learners build vocabulary from websites, YouTube subtitles and PDF documents. The platform identifies words that have not yet been learned, provides one-click translations, saves vocabulary to personal collections and supports review through flashcards, multiple training modes and spaced repetition.

Its Comprehension Level feature compares an article, video or PDF with each learner's saved vocabulary and estimates the percentage of known words. Content is grouped into clear difficulty ranges, and WordByWord shows the most frequent unfamiliar words together with an estimate of how much learning them may improve comprehension. This helps learners choose content suited to their current level and prepare a focused word list before reading or watching.

Spotlight Mode highlights unfamiliar words directly on webpages and uses learning statuses to distinguish new, learning and known vocabulary. Word statuses can be updated without leaving the page, allowing progress to be reflected during regular reading.

For YouTube, learners can translate and save words from subtitles, pause videos while reviewing vocabulary, navigate through subtitle lines and view a comprehension score before watching. For PDF documents, WordByWord provides in-document word translation and page-by-page vocabulary coverage for local and online files.

The platform supports more than 50 languages, including English, French, Spanish, German, Japanese, Korean, Italian, Portuguese, Chinese, Arabic and Russian. Comprehension scoring is based on the learner's own vocabulary rather than a general difficulty label.

Saved words can be organized into collections, reviewed with flashcards and spaced repetition, and imported or exported in Anki, CSV and PDF formats. Translations, saved words and collections are available without limits on the free plan.