When comparing Busuu vs Readlang, the Slant community recommends Readlang for most people. In the question“What are the best sites for learning foreign languages?” Readlang is ranked 4th while Busuu is ranked 9th. The most important reason people chose Readlang is:
You can read any content in your target language using the browser extension, and translate any words/sentences you don't know quickly.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Teaches realistic conversation behavior
Since Busuu puts learners in direct contact with natives, the learning is done in a realistic way - not an idealistic textbook way.
Pro Fast response time
For popular languages, translations can be received very quickly from real people.
Pro Teaches by theme
Instead of teaching words by most used, they are taught by case. This way, users can prepare for specific situations.
Pro Translates native content quickly
You can read any content in your target language using the browser extension, and translate any words/sentences you don't know quickly.
Pro Creates flashcards from words you don't know
Readlang takes the words you translate most often and turns them into flashcards for you to practice.
Pro You can import long texts, including whole books
This is impossible or very annoying with other similar services.
Cons
Con Ineffective "review" section
When a section is over, there is a multiple review session. Many of the questions are totally irrelevant and are not useful for learners.
Con Chat system doesn't support letters with accents
Busuu only accepts regular characters in the text fields, so non-native languages may be limited.
Con Not a good way to learn a language by itself
It's not your standard learning website with structured courses. Instead, it helps you get more familiar with your target language by translating content when needed.
This can be really beneficial for someone trying to improve their fluency, but isn't going to directly teach you grammar. Readlang is better used to supplement your learning while learning from structured courses.