Native Dart vs. JS Wrappers: The true cost of WebViews

Why WebViews kill performance in enterprise Flutter apps, and how Native Dart avoids the bridge penalty.

The Hidden Cost of "Write Once, Run Everywhere"

In the Flutter ecosystem, there is a constant temptation to reuse existing JavaScript libraries by wrapping them in a WebView. For simple content (like a Terms of Service page), this is fine. For a high-interaction component like a Gantt Chart, it is a performance disaster.

The Interaction Bridge

Every time a user touches a WebView, the event must travel:

  1. From the Native OS (iOS/Android)
  2. Through the Flutter Engine
  3. Across the Platform Channel
  4. Into the WebView Container
  5. To the JavaScript Engine

This round-trip introduces latency. In a complex drag-and-drop interface like a Gantt chart, this feels like "slushy" or "laggy" input.

The INP Penalty (2026)

Google's Interaction to Next Paint (INP) metric specifically targets this kind of lag. Search engines now penalize sites and wrapped apps that take too long to visually acknowledge a user interaction.

The Sovereign Solution: Native Dart

GanttSync and the legacy_gantt_chart package are built 100% in Dart.

  • Direct Skia/Impeller Rendering: We draw pixels directly to the canvas.
  • Zero Bridge: Touch events are handled synchronously in the Flutter gesture arena.
  • Predictable Performance: No garbage collection spikes from a secondary JS engine.

When building for Enterprise, "good enough" web wrappers are a liability. Native performance is the only way to guarantee a 120 FPS experience.