HealthChecks.MiniUI

HealthChecks.MiniUI is a tiny ASP.NET Core health page helper that renders a human-friendly HTML status page on top of Microsoft health checks.

What it does

• Renders health checks as a simple HTML page
• Serves humans and scripts from one endpoint, HTML for browsers and plain text for curl
• Shows status, description, duration, tags, and exception details
• Uses the existing Microsoft health check pipeline

How it looks

These screenshots are taken from the demo application.

Dark mode	Light mode	Exception pop-out

Installation

Install the package from NuGet:

dotnet add package WorldDirect.HealthChecks.MiniUI

Basic usage

Map the page in your app startup code:

// Microsoft.Extensions.HealthChecks
app.MapHealthChecks("/healthz");

// MiniUI HealthCheck page
app.MapSimpleHealthPage("/health", options =>
{
    options.Title = "My App Health";
});

Response status codes

By default, the page returns HTTP 200 for all overall health states (Healthy, Degraded, Unhealthy).

You can override this per status:

using Microsoft.AspNetCore.Http;

app.MapSimpleHealthPage("/health", options =>
{
    options.StatusCodes.Healthy = StatusCodes.Status200OK;
    options.StatusCodes.Degraded = StatusCodes.Status200OK;
    options.StatusCodes.Unhealthy = StatusCodes.Status503ServiceUnavailable;
});

Filtering which checks are executed

By default the page executes all registered health checks. Use Predicate to select a subset, for example by tag. Checks that are filtered out are not executed at all:

app.MapSimpleHealthPage("/health", options =>
{
    options.Predicate = registration => registration.Tags.Contains("ui");
});

This is the same Func<HealthCheckRegistration, bool> shape as HealthCheckOptions.Predicate used by MapHealthChecks.

Plain text output

Opt in with EnablePlainText to serve a text/plain rendering to clients that do not accept text/html, such as curl or a container health check. Browsers still get the HTML page.

app.MapSimpleHealthPage("/health", options =>
{
    options.EnablePlainText = true;
});

$ curl http://localhost:5000/health
Health Checks
Status:    Unhealthy
Duration:  1002.67 ms
Generated: 2026-09-05 09:12:33Z

| NAME    | STATUS    | DESCRIPTION          |   DURATION |
|---------|-----------|----------------------|------------|
| db      | Healthy   | connection ok        |     1.5 ms |
| failing | Unhealthy | queue backlog too... | 1002.67 ms |

Descriptions are shortened with ... so the table stays readable in a terminal.

Combine it with StatusCodes.Unhealthy so curl --fail works.

Demo app

The repository includes a small demo app in demo/HealthChecks.MiniUI.Demo.

Run it from the repo root:

dotnet run --project demo/HealthChecks.MiniUI.Demo/HealthChecks.MiniUI.Demo.csproj

Then open:

• /health for the MiniUI page (HTML in a browser, plain text for curl, 503 when unhealthy)
• /healthz for the plain MapHealthChecks response

Notes

• The UI is intentionally small and stateless.
• Route configuration is map-time, matching the usual ASP.NET Core endpoint style.
• The page is designed to stay simple and easy to extend later.