When using my phone, the toolbar is in the way. That is, there are buttons for Share, Collaborate, Tidy Up, Getting Started and a search icon and I do not see a way to get them out of the way.

In landscape orientation for the mobile version put the advertisements on the left or right, not the bottom. For code it helps to use landscape orientation but when we do there is much less horizontal space.

I began programming half a century ago. It is awesome to think I can use my phone to develop and test programs using an IDE. For me there was a time when we had only about one chance a day to run (test) our programs.

https://dotnetfiddle.net/vgdWI3

Func<Task<int>> al = async () =>
{ await Task.Delay(100); Console.WriteLine("AL"); return 1;};

var r = await al();

In fiddle (.NET 4.7.2) , I can't see "AL" which would printed by using .EXE from VS2019 or fiddle(.NET5).

Is it possible to add a debug mode checkbox so that System.Diagnostics.Debug.Assert can be enabled?

Bonus: Also enable line numbers in stack frames (currently, source info is inaccessible). https://dotnetfiddle.uservoice.com/forums/228764--net-fiddle-ideas/suggestions/43595874-enable-line-numbers-in-stack-traces

https://dotnetfiddle.net/qTKXnp

The Finally block is not executed while it always should.

sources:
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/try-finally

https://docs.microsoft.com/en-us/dotnet/csharp/fundamentals/exceptions/how-to-execute-cleanup-code-using-finally

It would come in handy to be able to click either the .NET Fiddle title in the top left corner, or a New Fiddle button to start over. Now, you have to refresh the page or go back to http://dotnetfiddle.net to create a new fiddle.

As far my experience goes using dotnetfiddle.net, the "Tidy Up" functionality only remove unnecessary lines reducing code readability

Source info in stack frames is currently inaccessible, and so stack traces do not contain line numbers.

I would like source file info (at least line number) to be made accessible, it would be a big help for debugging.

Add login with Microsoft account

Curley braces autocompletion would be so nice
and shortcut like cw + tab to write Console.WriteLine()

Is GC.Collect() implemented? With the 10-MB memory limit. A loop of 75k calls to MD5 ComputeHash runs out of memory. I cannot find a way to recycle memory.

https://dotnetfiddle.net/IjZfxF

With postsharp AOP is available for C#. I wanted to try out a sample code at postharp. I downloaded the nuget package, but it didn't work.

PostSharp extends the C# and VB languages with a notion of pattern. The result: shorter, cleaner code that’s easier to write and understand, contains fewer defects and is less expensive to maintain.

why we cant just add our <script src="xyz"> ourselves. Why adding our own css style and javascript in above our html panel doesnt work?

I have added Automapper v4.2.1 to create some snippets and getting the below error.
Run-time exception (line -1): Could not load type 'AutoMapper.MapperConfiguration' from assembly 'AutoMapper, Version=3.2.1.0, Culture=neutral, PublicKeyToken=be96cd2c38ef1005'.

It looks like that you need to add an assembly redirect field in config to map to take the version added.

Please refer the below fiddle for more
https://dotnetfiddle.net/Widget/fX0mdq

Please create My Fiddles on the left hand side Option's window or on right hand side (New window) so that one can easily switch between files if required.

It would be cool to mark some words as code and others as emphasized.

See this example: https://dotnetfiddle.net/nGSHTF

Typing return at the end of line 7 creates a new line with the wrong indentation. Adding spaces around the equals sign on line 8 causes the line to jump to the wrong indentation level.

This seems to be related to the code on line 7 which splits a string into an array of integers.

TOTAL IDEA :
1 - Font Size Change
2 - Set Automatic Color Syntax According to Commands (Like Notepad++)
3 - Add C++, Python , JavaScript , ... and more
4 - disable problem always set "Autorun on"
5 - Security Type : Public , Links , Private , Passworded
6 - Graph Output like Draw line.....