Stemmy vs Relingo.

Written by the team that makes Stemmy. Every fact about Relingo below comes from Relingo's own pricing page and Chrome Web Store listing, checked on 11 October 2026. The links are in the Sources list at the end.

The short answer

Both extensions help you learn English words from the pages you already read. The difference is who decides which words matter.

Relingo decides first. You set a difficulty level, and it highlights and translates the words it expects you not to know. Stemmy lets you decide. You highlight a word, click the Stemmy button beside it or press Alt+Shift+D, and you get the meaning that fits that sentence. AI meanings need a free account.

Relingo also covers ground Stemmy does not: bilingual subtitles on YouTube, Netflix and other video sites, and translation into several other languages.

Two ways to meet new words online

Words flagged for you. A tool compares each page with a word list for your level and marks the words you probably have not met. This is quick and suits broad reading. The trade-off is that a level list is a general guess, so it may mark words you will never need and pass over a rare word that matters in your field.

Words you pick. You read normally. When a word stops you, you look it up, check that the meaning fits this sentence, and save it with the sentence. It takes more effort per word, but every saved word is one you met and wanted.

Whichever method you use, three habits do most of the work:

• Keep the sentence. A word with its original sentence is far easier to recall than a word with a bare definition.
• Review on a schedule. Short reviews spread over days beat one long session. Our guide to vocabulary flashcards explains why.
• Keep the list small and real. Twenty words you met at work beat two hundred from a generic list. For a hands-on routine with nothing but a notebook, see how to remember new English words while reading online.

What Relingo does

According to its Chrome Web Store listing, Relingo highlights and translates new and difficult words based on the difficulty level you set and the words you have collected. You build a personal vocabulary book as you read and watch videos, and collected words show up again in later reading. It offers flashcards, prompts and emails to refresh your memory. It supports bilingual subtitles and highlighted new words on YouTube, Netflix, TED and Coursera, and full-page immersive translation. The listing names Chinese, Korean, Japanese, Spanish, Portuguese and French as translation languages.

The listing shows 50,000 users and a rating of 4.6 out of 5 from 1K ratings, as of 23 October 2026.

Relingo has a free version and Premium. On the pricing page, the free version includes page and YouTube word highlights, dual subtitles, selection and sentence translation, immersive translation, saving words and examples, word training, a daily email and syncing settings across devices. It caps saved words at 50 and saved examples at 50. Premium removes those caps and adds an English-English dictionary, advanced word explanations, AI grammar analysis, word import and export, export to Anki, study reports and 10,000 monthly credits for advanced translation engines.

Premium is listed at $3.99 a month, $23.99 a year or $69.90 for lifetime access, with the yearly and lifetime prices marked as a 2026 discount. You can also buy credits without Premium, in packs from $10 for 100,000 credits, valid for a year; the page says dictionary lookups are free and credits unlock paid translation engines. Relingo's prices load with JavaScript and are marked as a limited discount, so check its pricing page before you decide.

What Stemmy does

Stemmy is a Chrome extension for reading in English. Highlight a word, click the Stemmy button beside it or press Alt+Shift+D, and the Ghost Card shows the meaning that fits the sentence, the word's roots (WordDNA) and its pronunciation. AI meanings need a free account.

Save the word and it goes into your Vocabulary Wallet with its meaning, the sentence you found it in and the page link. You can search your words, grouped into categories, in the side panel or the dashboard. Reviews bring back only the words that are due, in short spaced-repetition sessions (FSRS) that you rate Again, Hard, Good or Easy and can pause and resume.

A few extras build on the wallet. X-Ray scans a difficult page and shows which words are worth learning, which is the closest Stemmy gets to Relingo's highlighting, but only when you ask for it. AI Stories writes short passages from the words in your review queue. Immersion, which is optional, shows your saved words again on pages you read, with one click back to the original text. Wallet Letters, an optional beta, emails you your due words daily or weekly. The wallet syncs across signed-in Chrome browsers, and you can export and import it as JSON.

Free to install. No paid plan is offered today. AI features need a free account (Google Sign-In or email). Each account gets 150 free AI uses in total, once; Ghost Card lookups and cloud voice draw on them. Your wallet, reviews and settings are stored in your browser, and for a meaning only the word and the sentence around it go to the AI provider. Meanings are in English; Stemmy does not translate. The privacy page has the details.

Side by side

Relingo details from its pricing page and Chrome Web Store listing, as of 11 October 2026.

When Relingo is the better fit

Choose Relingo if you learn a lot from video, since its dual subtitles cover sites Stemmy does not touch. It also suits you if you prefer translations into Chinese, Korean, Japanese, Spanish, Portuguese or French, or if you like seeing unknown words marked before you start reading. If you already use Anki, Relingo's Premium export to Anki may save you a step.

When Stemmy is the better fit

Choose Stemmy if you read English at work or for an exam and want the meaning that fits the sentence, not a general translation. Stemmy keeps the sentence and page link with every word, reviews them with spaced repetition, and shows word roots, which help with families of related words. Our guides to root words and business English vocabulary show how that plays out. Stemmy has no paid plan today; AI meanings use your 150 free AI uses, and there is no limit on how many words the wallet holds.

Frequently asked questions

Is Relingo free?

Relingo has a free version and a paid Premium plan. As of 11 October 2026, its pricing page shows the free version capped at 50 saved words and 50 saved examples, and Premium at $3.99 a month, $23.99 a year or $69.90 for lifetime access, with the yearly and lifetime prices marked as a 2026 discount.

What is the main difference between Stemmy and Relingo?

Relingo highlights words it expects to be new for your level and translates them. Stemmy explains a word only when you highlight it and click the Stemmy button, or press Alt+Shift+D, shows the meaning that fits the sentence, and saves it with that sentence for spaced-repetition review. AI meanings in Stemmy need a free account.

Does Stemmy work with YouTube subtitles like Relingo?

No. Relingo offers bilingual subtitles on YouTube, Netflix, TED and Coursera. Stemmy works on the text of the pages you read in Chrome and does not offer subtitle features.

Can I export my words?

In Stemmy, you can export and import your Vocabulary Wallet as JSON. On Relingo's pricing page, word import and export and export to Anki are listed as Premium features.

Do I need an account to use Stemmy?

AI features need a free account (Google Sign-In or email). Each account gets 150 free AI uses in total, once, and Ghost Card lookups and cloud voice draw on them. Your wallet is stored in your browser.

Sources

• Relingo pricing page: free and Premium features, saved-word and example limits, Premium prices, credits. Checked 11 October 2026.
• Relingo on the Chrome Web Store: description, supported video sites, translation languages, users and rating. Checked 11 October 2026.