Glossa is a web-based language learning app that lets you upload your own PDFs and EPUBs and read them in 18 languages with click-to-translate, audio narration, and built-in spaced-repetition vocabulary practice. It turns any book you already want to read into a graded reader for the language you are learning.

What languages does Glossa support?

Glossa supports 18 languages: English, Spanish, French, German, Italian, Portuguese, Dutch, Swedish, Norwegian, Danish, Polish, Russian, Turkish, Arabic, Chinese (Simplified), Japanese, Korean, and Hindi. Coverage depends on available CEFR data; languages without curated CEFR lists fall back to a machine-learning difficulty classifier.

What file formats can I upload?

PDF and EPUB, up to 100 MB per file. Books upload directly from your browser to Azure Blob Storage via a short-lived signed URL — the application server never sees the raw bytes in transit.

Yes. The free tier includes 2 books and 10 distinct pages of reading, with every feature unlocked (translation, audio narration, vocabulary games). Pro is $14.99 per month or a one-time $4.99 7-day pass, and removes the book and page limits.

What is included in Pro?

Unlimited books, unlimited pages, AI-generated chapter summaries, and faster book processing. Pro removes limits rather than gating features — translation, audio narration, and vocabulary practice are also fully available on the free plan.

Does Glossa work on mobile?

Yes, Glossa runs in any modern mobile browser. There is no native iOS or Android app yet; the responsive web app is the only way to use Glossa on phones today.

Is my uploaded content private?

Yes. Uploaded books are stored in a private Azure Blob container accessible only to your account, are never shared with other users, and are never used to train AI models. We do not sell user data.

What is CEFR scoring and how does Glossa use it?

CEFR is the Common European Framework of Reference for Languages, a six-level scale from A1 (absolute beginner) to C2 (near-native). Glossa scores every word in your book on this scale and a difficulty slider in the reader controls which words get translated inline — lower slider shows more glosses for harder words, higher slider shows fewer glosses and more original text.

How does the spaced-repetition vocabulary practice work?

Words you tap while reading are saved to your vocabulary list. Glossa surfaces them in short games — matching, fill-in-the-blank, multiple choice, parts-of-speech tagging, and sentence-scramble — scheduled so you re-encounter each word at increasing intervals based on how confidently you answered last time.

How is Glossa different from Duolingo?

Duolingo teaches with a fixed curriculum of synthetic exercises. Glossa is a reader — you upload real books you actually want to read, and translation and vocabulary practice are built around that content. Duolingo suits absolute beginners; Glossa suits learners who can read elementary sentences and want to engage with longer material.

How is Glossa different from LingQ?

LingQ has a built-in catalog of curated lessons and a learner community. Glossa lets you upload any PDF or EPUB and adds CEFR-adaptive interlinear translation, which LingQ does not offer. LingQ has more pre-curated content; Glossa gives you more control over what you read.

How is Glossa different from Readlang?

Readlang is primarily a browser extension for translating words in web articles. Glossa is book-centric — built around uploading PDFs and EPUBs, with audio narration, CEFR-adaptive glossing, and structured vocabulary games. Choose Readlang for web articles; choose Glossa for full books.

Can I import books from Project Gutenberg?

Yes. Glossa has a built-in browser for the Project Gutenberg catalog of public-domain titles. Pick a book in your target language and it imports in seconds without leaving the app.

What voices does Glossa use for audio narration?

Azure Neural Text-to-Speech voices, native-speaker quality in each supported language. Every user gets a default voice per language; additional voices can be unlocked using Glossa Points earned through reading.

LingQ alternatives (2026): picked by what actually bothers you

Prices checked July 2026. Disclosure: Glossa is our app and appears below — judged on the same terms as everything else, limits included.

LingQ is the veteran of input-based language learning, and for some people it’s exactly right. But the reasons people go looking for an alternative are remarkably consistent, and the right replacement depends entirely on which reason is yours. So instead of a generic top-ten, here’s the list organised by complaint.

“The free tier is a demo”

LingQ’s free plan caps at 20 saved words — enough to evaluate the interface, not to learn with. If you want a genuinely usable free tier:

Readlang — free gives unlimited single-word translations (phrase translations capped daily, 200 stored words). The most usable free tier of any hosted reader.
LWT / LinguaCafe — fully free, open-source, self-hosted (see below).
Glossa — free covers two full books and 10 pages of reading with everything switched on.

“$14.99/month is too much for what I use”

LingQ Premium runs $14.99/month ($119.99/year). If you mostly read and skim the rest of the ecosystem:

Readlang Premium — $6/month ($48/year): the same core loop (import, tap, flashcards) at less than half the price, web-only.
Smart Book — ~$1.99/month or ~$25 once: a native iOS/Android reader with parallel translation, switchable engines (incl. DeepL), chapter TTS, and Anki export. Almost free by category standards.
Linga — $5.49/month with a lifetime option: tidy iOS-first reader; the catch is it teaches only six languages.

“The interface is exhausting”

The most common complaint isn’t price — it’s that LingQ does everything, everywhere, at once: word statuses to maintain, coins, streaks, avatars, imports, playlists. Two different escapes:

Readlang, if you want the same tap-to-translate model with the chrome stripped away.
Glossa, if the tapping itself is the fatigue. Its reader inverts the model: instead of you tapping unknown words, adaptive interlinear glosses appear under the words you’re likely not to know — calibrated to your level, fading as you learn — so you read, and the lookups come to you. (How that format works; full head-to-head: Glossa vs LingQ.) Web app, 18 languages, $14.99/month or a $4.99 7-day pass — same price as LingQ at the top, much cheaper to actually try.

“I learn from video, not books”

Language Reactor (free core, Pro ~$6/month) owns this niche: dual subtitles and popup dictionary on Netflix and YouTube, in a desktop Chrome extension. It has a lesser-known text mode, but video is the reason to choose it.

“I want curated content with audio, not imports”

Beelinguapp (~$7/month, mobile-only) serves curated bilingual stories with karaoke-style narration — pleasant, low-effort, and honest about what it is. You cannot import your own books, and development has visibly slowed; treat it as a supplement, not a home.

“I’d rather own it than rent it”

The self-hosted corner is real and free: Learning With Texts (the ancient-but-working original — PHP, dated UI, term tracking, Anki export) and LinguaCafe (the modern Docker-deployed take — EPUB import, dictionary popups, built-in review; still pre-1.0). The price is your setup time and your own backups.

When to just stay with LingQ

Honesty cuts both ways. Keep LingQ if you genuinely use the whole ecosystem — books and YouTube and podcasts and transcription in one subscription — or if years of accumulated word statuses are doing real work for you (no alternative imports them). Nothing below replaces the breadth; the alternatives win on focus, price, or reading experience, not on doing more.

The short version

Cheapest capable replacement: Readlang
Best reading experience, own books, no tapping: Glossa
Native mobile, offline, one-time price: Smart Book
Video learner: Language Reactor
Free forever, your server: LinguaCafe or LWT

For the full nine-app comparison with a feature table, see best apps to read books in a foreign language.