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.

1. Putting Business Logic Directly in .razor Files

2. Ignoring Proper Naming Conventions

3. Overusing @code Blocks Instead of Reusable Services

4. Incorrect State Management

5. Calling APIs Directly from Components Everywhere

6. Not Handling Errors Gracefully

7. Poor Folder Structure

8. Ignoring Performance Basics

9. Hardcoding Configuration Values

10. Treating Blazor Like JavaScript Frameworks

Final Thoughts

1. Putting Business Logic Directly in `.razor` Files

3. Overusing `@code` Blocks Instead of Reusable Services