Lexo vs Readlang: a reading tool or a library?
Readlang turns any web page into a reading lesson, with flashcards built in. Lexo gives you narrated classic novels at your level. Which fits how you read?
Readlang and Lexo both help you read in a language you’re still learning, and in both you can tap or click a word to see what it means. Beyond that they’re different kinds of thing. Readlang is a tool: you bring the text, from a web page, an ebook or its library, and it gives you translations and flashcards. Lexo is a library: classic novels rewritten at your level, narrated, with every word explained in the sentence you found it in.
We make Lexo, so read this with that in mind. We’ve tried to describe Readlang the way its own users would and to be plain about what Lexo doesn’t do. It was checked in October 2026 against Readlang’s site, blog and forum. Readlang’s plans and limits change, so check its pricing page for current details.
The short answer
Choose Readlang if you want to read anything on the web with instant translations and have your flashcards made for you, especially on a computer, and if you’d like to start free. Choose Lexo if you want whole books pitched at your level, narrated in full, with each word explained in context, in a native app for iPhone and iPad that works offline. Readlang is the better fit for reading the internet; Lexo is built for reading books.
At a glance
| Readlang | Lexo | |
|---|---|---|
| What it is | A web reader and browser extension that adds translation and flashcards to any text | A library of classic novels rewritten at your level |
| What you read | Any web page, pasted text, DRM-free EPUBs, YouTube transcripts, its public library, and AI-generated stories | About 100 classics, from Sherlock Holmes to Little Women |
| Levels | Whatever you choose; library texts carry rough A1 to C2 ratings, and the Story Bot writes at your level | CEFR A2 to C2, chosen per book |
| Help with words | Click a word or drag across a phrase for a translation; AI explanations that use the surrounding sentence | Tap any word: its meaning in this sentence, base form, part of speech, idiom, and a translation of the sentence |
| Audio | Read Aloud with synthesized voices and word highlighting; transcription of your own audio on paid plans | The whole book narrated, with character voices and word-by-word highlighting; every word playable |
| Review | Spaced-repetition flashcards made from your lookups, with the original sentence; export to Anki | A saved Words list you can go back over; no spaced repetition |
| Languages | More than 100 | About 80 |
| Offline | No | Yes; books download to your device |
| Platforms | Web (works in phone and tablet browsers); extension for desktop Chrome and Edge; bookmarklet for other browsers | iPhone and iPad (iOS 18 or later) |
| Account | Required | None; purchases go through your Apple ID |
| How you pay | Free plan with daily limits; low-cost Premium and Premium Plus subscriptions | $4.99 a book, or Lexo Plus at $4.99 a month for two book credits (planned US launch prices) |
| Can you use it today? | Yes | Not yet; in beta, launching on the App Store soon |
What Readlang does well
Readlang has been around since 2013. It was built by Steve Ridout, sold to Duolingo in 2017 and bought back by Ridout in 2023, and it still has the focus of a tool made and run by one person.
It works on whatever you’re reading. Open a news article in Chrome, click the extension, and every word on the page is a click away from a translation. Drag across a phrase and you get the phrase translated as a unit. You can also paste in text, upload a DRM-free EPUB, or import a YouTube video that has a transcript.
Your flashcards make themselves. Every word you look up becomes a card that keeps the sentence you found it in, and you can practice them with spaced repetition, as fill-in-the-blank cards or multiple choice. If you already use Anki, you can export them there.
The free plan is useful. Single-word translations are unlimited for free, with daily limits on phrase translations and AI explanations. The paid plans are inexpensive.
It has grown thoughtful AI features. Explanations take the whole sentence into account. The Story Bot, on paid plans, writes stories at your level on topics you choose, in genres from classic fiction to biography. There’s an AI conversation partner for written practice, and Read Aloud plays whole texts with each word highlighted.
It covers more than 100 languages.
Two limits are worth knowing. There’s no native mobile app (the website is designed to work well on phones, and you can add it to your home screen), and there’s no offline mode.
What Lexo does differently
Lexo starts from the book rather than the tool. You choose a classic, such as The Hound of the Baskervilles, Frankenstein or Little Women, and a level from A2 to C2. The book has been rewritten at that level in the language you’re learning, so most of each page is within reach and your taps are for the words that really stop you. At C1 it’s close to the original, lightly condensed; at C2 it’s the complete novel. See our levels guide for what each level reads like.
A tap brings up a card with the word’s meaning in this sentence, its base form and part of speech, the meaning of any phrase or idiom it belongs to, and a translation of the whole sentence into your own language. You can save the word to your Words list. The book is narrated from start to finish, with different voices for different characters and the words highlighted as they’re read, and a sentence-by-sentence mode shows one sentence at a time with its audio and translation.
Lexo is a native app for iPhone and iPad, with paginated pages, serif type and reading themes (Paper, Sepia, Slate and Night). Books download, so you can read and listen offline, and there’s no account to create. It covers about 80 languages, with explanations in your own language. The adaptations, glosses and narration are produced with AI models, guided by the CEFR level descriptors and checked automatically, and most editions are written when the first reader asks for one: chapter 1 is ready in a few minutes and the rest follows while you read.
Bring your own text, or read at a set level
With Readlang, you’re the editor. That’s its appeal: the internet is endless, and reading what genuinely interests you keeps you coming back. The work is in finding texts at the right difficulty. Most native web writing is hard for an intermediate learner, and Readlang’s own developer describes its library’s level ratings as rough guides. The Story Bot is a smart answer to that problem, since it can write something at your level on a topic you pick.
Lexo takes that work off your hands, for a narrower shelf. Hu and Nation (2000, “Unknown vocabulary density and reading comprehension”) found that most readers needed to know about 98% of the words in a story to understand it adequately without help. Lexo’s answer is to rewrite the whole book at your level, so you can read for the plot rather than the vocabulary. That’s the heart of extensive reading as Day and Bamford (1998, Extensive Reading in the Second Language Classroom) describe it: lots of reading, comfortably within your ability. More in the 98% rule and extensive reading.
The two also differ in what happens after the lookup. Readlang turns lookups into a study system. Lexo keeps you in the story, with narration to carry you forward, and keeps review simple: a list of saved words to go back over.
Who should choose Readlang
- You read a lot on the web, especially on a laptop, and want translations wherever you are.
- You want flashcards built for you, with context sentences and spaced repetition, and perhaps exported to Anki.
- You want a free start. Unlimited single-word lookups cost nothing.
- You want AI help on your terms: stories at your level on topics you choose, explanations of tricky sentences, and written conversation practice.
- Your language is one Lexo doesn’t cover, or you use Android or a computer.
Who should choose Lexo
- You want to read books, not just articles. Lexo’s library is whole classics, chosen because their stories survive retelling.
- You want the level handled for you. Each book is rewritten at your level, so you’re not hunting for texts that are hard enough to teach you something but easy enough to enjoy.
- You want to listen as well as read. Books are narrated in full, with character voices and the text highlighted as it’s read.
- You read on iPhone or iPad, on the sofa, on the train, or offline.
- You’d rather not manage a deck. The reading itself is the practice, and the Words list is there if you want it.
Lexo is in beta and launching on the App Store soon. Get notified at launch. If you’re comparing reading tools, see Lexo vs LingQ and the best apps to learn a language by reading.
Questions
Can I use Readlang on my phone?
Yes, in your phone's browser. Readlang is a web app designed to work on phones and tablets, and you can add it to your home screen. As of October 2026 there's no native app in the App Store or Google Play, and no offline mode. Lexo is a native iPhone and iPad app that works offline.
Does Lexo have flashcards like Readlang?
Not in the same way. In Lexo you can save words to a Words list and go back over them one at a time, with the meaning and the sentence each came from, but nothing is scored or scheduled: there's no spaced repetition. If you want flashcards built automatically from what you read, Readlang does that well, and it can export them to Anki.
Can I read my own texts in Lexo?
No. Lexo is a library of about 100 classics, each rewritten at five levels from A2 to C2. To read web pages, articles, ebooks or texts you paste in, use a tool such as Readlang.
Which is better for listening practice?
Lexo is built around it: books come with full narration, with different voices for different characters and the words highlighted as they're read (in seven of Lexo's languages, narration is still to come). Readlang's Read Aloud can read any text with synthesized voices and highlight each word, and its paid plans add higher-quality voices. Both use synthetic voices.