When comparing Ayni 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 Ayni is ranked 24th. 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 Focuses on practice
It is focused on practice with penpals and it provides content about how to get the most out of language exchange.
Pro Engaging conversations
Writing a real person is much more engaging than repeating words from a program. You are more likely to continue with Ayni than other programs because you can actually have a conversation instead of simply learning words and phrases.
Pro Free
Pro Great to find an active penpal
This is a small community (+2000 active users) but active, as it does not look like a social network but more like a collaborative platform for matching.
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 Not a lot of users to interact with
It is very hard to find a Japanese or Korean pen-pal on Ayni. However even some of the more popular languages don't have many users to talk with.
Con Website has a lot of grammar mistakes
The website itself (English version) has quite a few grammar errors throughout. The lack of attention put into the site, especially language errors on a language site, are concerning.
Con Not recommended for beginners
There is no content if you start learning a language from scratch.
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.