How to log error in .NET Core?

Anubhav Sharma 354 16 Mar 2026

1 Answers

Anubhav Sharma 16 Mar 2026

In ASP.NET Core, error logging is done using ILogger.
It helps to save errors in file, database, console, or logging tools.

1. Use ILogger in Controller

public class HomeController : Controller
{
    private readonly ILogger<HomeController> _logger;

    public HomeController(ILogger<HomeController> logger)
    {
        _logger = logger;
    }

    public IActionResult Index()
    {
        try
        {
            int x = 10;
            int y = 0;
            int z = x / y;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error occurred in Index");
        }

        return View();
    }
}

This will log error in console / default logger.

2. Log in Middleware / API

try
{
    // code
}
catch (Exception ex)
{
    logger.LogError(ex, "API Error");
}

3. Log Levels

LogInformation()
LogWarning()
LogError()
LogCritical()
LogDebug()

Example:

_logger.LogError("Error message");

4. Use Serilog (Production)

Most used logging tool with .NET Core

Serilog
NLog
Log4Net

Example:

builder.Host.UseSerilog();

Short Answer for Interview:

In .NET Core we log errors using ILogger. It supports multiple log providers like Console, File, Serilog, NLog, etc.
We use _logger.LogError(ex, "message") inside try-catch or middleware.

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