10 Blazor Coding Mistakes I See in Real Projects (and How to Avoid Them)

Blazor is a powerful framework for building modern web applications using C#, but in real-world projects, I repeatedly see the same mistakes that hurt performance, maintainability, and security.

After working on enterprise and SaaS Blazor applications for years, here are the 10 most common Blazor coding mistakes I see in production — and what you should do instead.

1. Putting Business Logic Directly in .razor Files

Many Blazor apps start simple, but over time .razor files turn into massive files full of logic.

Why it’s a problem

• Hard to test

• Difficult to maintain

• Poor separation of concerns

Better approach

• Move logic to code-behind files ( .razor.cs )

• Or use service classes and inject them into components

"Razor files should focus on UI, not business rules."

2. Ignoring Proper Naming Conventions

Inconsistent naming is one of the fastest ways to make a Blazor codebase confusing.

Common mistakes

• Components named test.razor , page1.razor

• Methods like DoStuff() or Handle()

Better approach

• Use clear, intention-revealing names
  InvoiceList.razor , UserProfileCard.razor

• Follow consistent casing and suffix rules

Good naming is not optional — it’s a productivity multiplier.

3. Overusing @code Blocks Instead of Reusable Services

Developers often copy and paste logic between components.

Why these hurts

• Code duplication

• Bugs fixed in one place but not others

Better approach

• Extract shared logic into services

• Register them using dependency injection

Blazor’s DI system is there for a reason — use it.

4. Incorrect State Management

State bugs are subtle and painful.

Common issues

• Relying too much on static variables

• Losing state on refresh (especially in WASM)

• Confusing scoped vs singleton services

Better approach

• Understand component lifecycle

• Use scoped services wisely

• Persist important state explicitly

State management should be intentional, not accidental.

5. Calling APIs Directly from Components Everywhere

Calling APIs inside every component leads to tight coupling.

Why it’s risky

• Hard to mock

• Hard to refactor

• Poor error handling consistency

Better approach

• Create API service layers

• Centralize error handling and retries

Your components will become cleaner instantly.

6. Not Handling Errors Gracefully

Unhandled exceptions in Blazor can break the entire UI.

Common mistakes

• No try/catch around async calls

• No user-friendly error messages

Better approach

• Wrap async operations carefully

• Use error boundaries

• Log errors properly

Production apps must fail gracefully .

7. Poor Folder Structure

Flat or random folder structures don’t scale.

What I often see

• All components in one folder

• No separation between pages, shared components, and features

Better approach

• Feature-based folders

• Clear separation for:

  • Pages

  • Components

  • Services

  • Models

Structure is a form of documentation.

8. Ignoring Performance Basics

Blazor performance issues are usually self-inflicted.

Common mistakes

• Heavy OnAfterRenderAsync

• Unnecessary re-rendering

• Large component trees

Better approach

• Use @key correctly

• Minimize re-renders

• Measure before optimizing

Small changes can have a huge impact.

9. Hardcoding Configuration Values

Hardcoded URLs, keys, and flags appear far too often.

Why this is dangerous

• Security risks

• Difficult environment changes

Better approach

• Use appsettings.json

• Environment-specific configuration

• Secure secrets properly

Configuration should never live in UI code.

10. Treating Blazor Like JavaScript Frameworks

Blazor is not React or Angular .

Common mistake

• Forcing JS-style patterns into Blazor

• Ignoring C# and .NET strengths

Better approach

• Embrace strong typing

• Use C# patterns

• Leverage .NET libraries

Blazor shines when you use it the Blazor way .

Final Thoughts

Most Blazor problems are not framework issues — they’re coding standard issues .

Once you apply consistent rules for:

• Naming

• Structure

• State

• Error handling

• Performance

your Blazor apps become cleaner, faster, and easier to scale.