🚀 Blazor Performance Tip (That Actually Matters in Production)

One of the most overlooked performance killers in Blazor apps is unnecessary re-rendering.

💡 Quick tip:

Use @key strategically in your components.

Why?

When rendering lists or dynamic UI, Blazor uses a diffing algorithm.

Without @key, it may re-use DOM elements incorrectly — causing:

• UI glitches

• Lost input state

• Extra rendering work

✅ Example:

Instead of:

@foreach (var item in items) { <MyComponent Data="item" /> }

Use:

@foreach (var item in items) { <MyComponent @key="item.Id" Data="item" /> }

🔍 What this does:

It tells Blazor exactly how to track elements → resulting in:

• More predictable UI behavior

• Better rendering performance

• Fewer subtle bugs

⚠️ Crucial Warning: Avoid using the array index (e.g., @key="index") as your key if the collection is dynamic (adding, removing, or reordering items).

Always use a unique, immutable identifier (like a Database ID or GUID).
Using an index as a key often defeats the purpose and can actually cause bugs if the items change position in the list.

⚠️ When it matters most:

• Large lists

• Frequently updated components

• Real-time dashboards

Small detail. Big impact.🚀

#ablikim #Blazor #DotNet #Performance #WebDevelopment #CSharp #SoftwareEngineering