What Paralelo is
Paralelo is a reading app for people learning a language. You read a real book in the language you are learning, and the translation sits beside it, aligned phrase by phrase: hover or tap a group of words on one side and its counterpart lights up on the other.
It is built for reading whole books, not exercises. Your place is kept across devices, a passage from every title is free to read without an account, and a free account opens every book in full.
How the translations are made
Every translation on Paralelo is made by a language model, and every page says so. The original is first cut into numbered paragraphs, and each paragraph is translated in turn, so paragraph 412 of the original is paragraph 412 of every translation.
A glossary of the names in each book travels with the translation, so a character keeps one name from the first chapter to the last.
How the alignment works
Once a paragraph is translated, a word-alignment model links the words of the original to the words of the translation. Those links are grouped into phrases, which is what lights up when you hover: a phrase and its rendering, not a word-for-word gloss.
Alignment is the part of Paralelo that has no equivalent on a printed page. It is also why switching the translation language keeps your place: every language shares the original’s paragraph numbers.
How a translation is checked
Before a translation is published it passes a set of mechanical checks: every paragraph is present, lengths are plausible, the text is in the right language, numbers and names are carried over consistently, nothing of the instructions leaked into the text, enough words are aligned, and a sample reads as natural prose.
A translation that fails is not published. One that passes is then read by a person, a sample of paragraphs beside the original, and a translation that reads badly is taken down.
Where the books come from
The texts come from Project Gutenberg, which publishes books whose copyright has expired. Each book page names the Gutenberg edition it was made from.
Author pages are written with AI from Wikipedia and Wikidata, checked against those sources before they are published, and say so on the page. Portraits come from Wikimedia Commons and are in the public domain.
Who makes Paralelo
Paralelo is made in France by Arthur Renaud, who designs and builds it.
Questions, corrections and suggestions are welcome: hello@paralelo.app