Flutter Web parity, explained
Build once, run everywhere. Here is how the Kletso SDK reaches feature parity across iOS, Android and Web.
Priya Nair· Engineering · 5 Sept 2026 · 6 min read
Most vendor SDKs for Flutter are thin wrappers around native iOS and Android libraries. That means platform channels, a fixed native UI, and no Flutter Web support at all.
Pure Dart, on purpose
The Kletso SDK is written in Dart and talks to the backend over WebSocket and REST. There are no platform channels and no WebView. The same package runs on iOS, Android, Flutter Web, macOS, Windows and Linux.
Why it matters for generative UI
Because rendering happens in your widget tree, your registered renderers are ordinary Flutter widgets. They pick up your theme, your fonts and your state management without any bridge.
Performance
Streaming replies arrive as tokens and tool-call events over a single socket. On web we fall back to server-sent events when a proxy blocks sockets. Typical first-token latency is well under a second on modern providers.
Build once, ship everywhere, and keep your UI yours.
