Using .NET Hot Reload in Rider: Enable, Edit, and Verify Live Changes

Edit code while debugging with .NET Hot Reload in Rider

When a Rider debugging session is active, you can change C# source files and see the updates applied instantly without stopping the process.

Worked example: a .NET 6 console application

1. Open Rider and create a new console project targeting .NET 6.0 (for example, dotnet new console -n HotReloadDemo in a terminal).
2. Open the generated Program.cs file and replace its contents with:

using System;

namespace HotReloadDemo
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            Console.WriteLine(\"Original message\");
            // Keep the process alive so you can observe the change
            while (!Console.KeyAvailable)
            {
                Thread.Sleep(200);
            }
        }
    }
}

Place a breakpoint on the Console.WriteLine line, then start debugging (Debug → Start Debugging). Ensure the lightning‑bolt Hot Reload icon on the debugger toolbar is highlighted; if it is not, enable it via Settings → Build, Execution, Deployment → Debugger → Enable Hot Reload.

While the debugger is stopped at the breakpoint, edit the string inside Console.WriteLine to, for example, \"Updated message via Hot Reload\" and save the file (Ctrl+S). Rider will push the change to the running app; the status bar shows a lightning‑bolt notification and the next time the breakpoint is hit you will see the updated output in the console window.

Limitations and common mistakes

• SDK version: Hot Reload requires .NET SDK 6.0 or later. Using an older SDK will cause Rider to fall back to a full restart on each change.
• Launching without a debugger: Pressing Ctrl+F5 (run without debugging) disables Hot Reload because the feature relies on the debugger infrastructure.
• Editing outside the opened solution: Changes to files that are not part of the current Rider solution are not sent to the process.
• Hot Reload toggle disabled: If the setting is turned off, the IDE will not attempt live updates and will restart the app instead.
• Profiler or analytic agents: Running the app under a profiler, certain diagnostic tools, or with the DOTNET_STARTUP_HOOKS environment variable set can block Hot Reload.
• Method signature changes: Adding, removing, or changing parameters or return types often cannot be applied live; Rider will notify you and require a manual restart.
• Static field values: Hot Reload does not re‑initialize static fields, so their values persist across edits, which may lead to unexpected behavior.

Practical verification

After performing the edit‑save step, check the following:

• The debugger toolbar’s Hot Reload icon remains highlighted.
• The status bar displays a short lightning‑bolt message indicating that changes were applied.
• At the breakpoint, the console shows the new string you entered.
• If you see a notification that Hot Reload failed, consult the IDE’s event log for details and consider a restart.