Glossa vs Readlang
An honest comparison. Last reviewed 26 September 2026; Readlang details checked against readlang.com and Readlang’s blog, linked under Sources, on that date.
These two tools are built for different reading. Readlang is a cheap, broad click-to-translate layer for whatever you read online: a browser extension for any web page, an eReader for texts you upload, 100+ languages, $6 a month. Glossa is for one book at a time — including the ones that only exist as a PDF — and for translation that gets out of your way as your reading improves: only the words above your level are glossed, and that set shrinks month by month.
At a glance
| Glossa | Readlang | |
|---|---|---|
| Upload EPUB or plain text | Yes | Yes (DRM-free EPUB, .txt) |
| Upload PDFs | Yes | No — convert to text first |
| Browser extension for web pages | No | Yes |
| Click-to-translate | Yes | Yes |
| Audio narration of the text | Yes — neural voices, included | Yes — your browser’s voices; higher-quality voices for words and phrases on Premium, and for whole texts on Premium Plus |
| Interlinear translation tied to your level | Yes — only words above your level, adjustable | No — click a word, or reveal all |
| Vocabulary review | In-app games (matching, cloze, scramble, more) | Built-in spaced-repetition flashcards, plus Anki export |
| Project Gutenberg titles | Browse and open them inside the app | Download from Gutenberg, then upload |
| Price | $14.99/month, $9.99/month billed yearly, or a $4.99 7-day pass | $6/month or $48/year; Premium Plus $15/month |
When to choose Readlang
Readlang is the right call if your reading is spread across the open web — news sites, blogs, Wikipedia in your target language. Its browser extension translates words inline on any page you visit, which Glossa does not do at all: Glossa only reads what you bring into it. Readlang is also the cheaper habit at $6 a month against $14.99, and it covers 100+ languages where Glossa covers 13. If your language isn’t one of those 13, the decision is already made.
When to choose Glossa
Two things decide it. The first is PDFs. Readlang takes EPUB and plain text, so a textbook, a journal archive or an out-of-print book that exists only as a PDF has to be converted first — and conversion is where the layout goes. Glossa reads the PDF directly, finds where the front matter ends and the book begins, and keeps the chapters.
The second is what the page looks like. Readlang has two states: click a word to see it, or reveal everything. Glossa has a level. Translations are written between the lines for the words above it and nothing else, so an easy paragraph reads clean and a hard one arrives pre-glossed — no clicking, no breaking the sentence to look something up. The level follows you: as you stop needing a word, it stops appearing, and the reader shows you that trend in your own numbers rather than asking you to take it on faith.
Around that: narration on any sentence with neural voices included rather than reserved for a top tier, Project Gutenberg browsable from inside the app instead of downloaded and re-uploaded, and vocabulary practice as games built from the book you just read.
Try Glossa
The free tier covers two books and 10 pages of reading — enough to compare it directly against your current Readlang workflow on something book-sized.
Sources
Official pages each competitor claim was checked against, on 26 September 2026. Prices change; if one of these disagrees with this page, trust the source and tell us at [email protected].
- Readlang — Pricing · Features · PDF import (forum answer) · Voices (blog, May 2026)