This study explores the pragmatics and metapragmatics of elasticity via elastic language in online medical information delivery as a way of avoiding miscommunication. Moreover, an evaluative dimension that extends beyond the viewpoint of the analyst is incorporated into pragmatics, by investigating participants’ feedback on the use of EL, which triangulate the findings of this study. From a cross-cultural (Australia and Taiwan) perspective, this study presents an account of harmony and disharmony between professional medical websites and the potential users of these websites. This study finds that elastic language performed eleven first- and second-order functions. Elastic language was preferred more by the Taiwanese participants than by the Australians. The findings further develop the elasticity theory by adding a metapragmatic dimension, inform and assist the online writer to successfully develop healthcare literacy, and make online medical information credible and suitable for public education.