Supporting older browsers and iOS/Android versions

[IvoJansch]

I'm developing an app for a client on top of their ArcGis platform. They have a target audience with an age demographic that unfortunately still uses older devices. I've noticed that the current Swift SDK requires iOS 16 or up. Therefor we would like to offer people with older devices a web version as alternative. However the current JavaScript SDK requires Safari 17, which is only available from iOS 17 and up. 

Is there a way to support older browsers, for example by using an older version of the Javascript SDK, and would that still be supported by ESRI? Or what are others doing to support older browsers and older devices?

Thanks!

[JoshuaBixby]

Start by looking at ArcGIS Maps SDK for JavaScript Life Cycle.  The oldest supported version is 4.24, which supports down to Safari 14, but that version of the SDK also is retired on 12/01/2025.  ArcGIS Maps SDK for JavaScript 4.27 was the last version to support Safari 15, and it doesn't retire until 11/01/2026, so that is probably your best bet for now.

Although Apple sometimes backports critical security patches to unsupported versions of iOS, it isn't guaranteed, and Apple currently supports iOS 18 and newer.  Supporting unsupported software is one thing, doing new development on unsupported software is something else entirely.