English Dictionary Extension for Chrome & Firefox | Dejavu English
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Free browser extension for Chrome, Edge and Firefox

Save the words and phrases you want to learn

When you read English on websites, the words and useful expressions you want to learn need a place to be saved and reviewed regularly. This extension was created exactly for that purpose: look up words, save phrases and keep everything synchronized with the Dejavu English web app. Dejavu tracks when you need to see them again and uses spaced repetition to move them into long-term memory.

  • Save the words and expressions you want to remember
  • Review them regularly so you can use them in conversation
  • Keep everything synchronized with Dejavu English
Google Chrome Add to Chrome Mozilla Firefox Add to Firefox
Installed from the official browser stores.
Dejavu dictionary extension showing the meaning, pronunciation and CEFR level of the word “reluctant”

Save what you want to learn. Remember it later.

Save useful words and expressions while you browse, then review them at the right intervals. The extension works fully synchronized with the Dejavu English web app, so the English you meet can become part of your long-term memory.

Words

A word you care about? Double-click it

On any website, double-click a word. You get a proper dictionary entry: meaning in your language, English definition, CEFR level, how common it is, pronunciation, examples and synonyms. One click sends it to your word notebook. From there Dejavu tracks the reviews.

  • No copy and paste, and you stay on the page
  • Turn double-click off any time if you prefer typing or right-click
The extension dictionary opened by double-clicking a word, showing meaning, IPA pronunciation, B2 level, example sentence and synonyms
Context

Select a sentence to learn a word in context

Select a sentence and right-click. The extension shows the root and base form of the word you are looking up, so inflected forms do not get in the way. You learn what the word means in that sentence and how it is used in context. The sentence is saved with the word in your notebook.

  • Works with a sentence you select or one you type yourself
  • Context is what makes a word usable later
The extension extracting the words committee, reluctant, approve, proposal and evidence from a selected sentence
Phrases

The phrases that make you sound fluent

Fluency is rarely a pile of single words. Select an expression, translate it naturally, and save it to your phrase notebook. Dejavu will remind you to practise it with spaced repetition — that is how eloquence is built, from English you actually met.

  • Listen to the phrase
  • See similar phrases already in your notebook
The extension translating the phrase “It’s not my cup of tea” and offering to save it to the phrase notebook
Reader

How much of the article do you understand right now?

Send the article to Dejavu Reader. See how much you understand with your current knowledge and which words you already know. The text is cleaned up, known words are marked by memory stage, and new words are highlighted. Save the article and continue reading whenever you like.

  • Quick Save keeps the article without opening it
  • Analyse & Preview shows reading level and known-word coverage
The “This Page” tab of the extension, ready to analyse and save the open article to Dejavu Reader

Install from the official stores

Chrome Web Store

Chrome Web Store

For Chrome, Microsoft Edge, Brave and other Chromium browsers. Installed from the official Chrome Web Store listing.

Open Chrome Web Store
Firefox Add-ons

Firefox Add-ons

For Mozilla Firefox. Installed from the official Mozilla Add-ons listing, reviewed by Mozilla.

Open Firefox Add-ons

Getting started takes a minute

  1. Install the extension from the Chrome Web Store or Firefox Add-ons.
  2. Sign in once with your Dejavu English account — it stays signed in.
  3. On any English page, save a phrase that sounds right or look up a word you care about.
  4. Dejavu tracks the reviews and reminds you with spaced repetition until they stick.

What the extension can see

A dictionary that works on every page needs permission to read pages. Here is exactly what that means:

  • The word or sentence you double-click or select is sent to Dejavu English to be looked up. Nothing else on the page is read.
  • Article text leaves your browser only when you press Analyse & Preview or Quick Save yourself.
  • Your sign-in is kept as a token on your own device, per browser. No password is stored in the extension.
  • There are no ads and no third-party trackers inside the extension.

Frequently asked questions

Is the extension free?

Yes. The extension is free and works with a free Dejavu English account. Some advanced study features on the website belong to the Pro plan, but looking words up, saving them and reading pages do not.

Which browsers does it support?

Chrome, Microsoft Edge, Brave and other Chromium-based browsers through the Chrome Web Store, and Mozilla Firefox through Firefox Add-ons. Install it once per browser; each browser keeps its own sign-in.

Do I have to leave the page to look a word up?

No. Double-clicking a word opens the dictionary over the page. Selecting a sentence and using the right-click menu works the same way.

Can I turn double-click lookup off?

Yes. There is a switch at the bottom of the extension’s Dictionary tab. Turn it off and words are only looked up when you type them or use the right-click menu.

What happens to the words and phrases I save?

They go to your notebooks with the sentence you met them in. Dejavu tracks how often you need to see them and brings them back with spaced repetition, flashcards and pronunciation practice until they stick.

If this is what you have been looking for, start here

Install the extension, sign in once. Save the English you meet. Dejavu will remind you until it is yours.

Google Chrome Add to Chrome Mozilla Firefox Add to Firefox