In 2018, Safari, Apple's browser, faced various compatibility challenges despite its advanced web technologies and unique features. While it maintained a significant share of the browser market, developers needed to ensure their websites were compatible with Safari due to its slower adaptation of new technologies compared to browsers like Chrome or Firefox. Key issues included lack of support for certain CSS features, some ECMA 6 capabilities, and specific multimedia formats such as Ogg and WebM. Additionally, Safari lagged behind in supporting Transport Layer Security (TLS) 1.3 and certain JavaScript APIs. However, Apple began improving Progressive Web App (PWA) support by implementing features like the Service Worker API and Web App Manifest, signaling a commitment to enhancing Safari's compatibility and performance. Despite these challenges, Safari remains backed by Apple and continues to be a relevant browser, necessitating cross-browser compatibility testing for developers.