http://uwb25d43nnzerbozmtviwn7unn7ku226tpsjyhy5n4st5cf3d4mtflqd.onion/posts/e2ee/index.html
OnionShare doesn’t implement any chat encryption on its own — it relies on the Tor onion service’s encryption. Cwtch and Briar both have more features (including the additional Tapir and BTP encryption protocols). The only advantage of OnionShare is that it is installed on Tails by default.