Online tools for .Net Core and Web development

10 Aug 2020

When you work for long enough on a given project, you kind of get comfortable with the tools and things eventually start to feel familiar. So it’s only natural to start feeling like you’re missing out and there might be newer and greater things out there, some exciting new languages, tools or techniques.

In this article, I’d like to show you some online tools that I found super helpful in my development work.

Develop & iterate faster

Remember the feeling when you need to set up a whole new project in VS just so you can play around with a new idea or test a new C# feature? Or even worse, write some temporary code in the an solution you’re developing and then forgetting to remove it, committing & deploying to prod? Dreadful, I know.

What if there was a tool that let you quickly write & run some C# code without too much fuss?

Looking for a comparison of C# REPLs? Check out this article: How to quickly run some C# without a project

.NET Fiddle

.NET Fiddle lets you run C# code in your browser. It has syntax and error highlighting, autocompletion and it runs the latest version of C#, so you get access to all the cool language features. To get that working, make sure to select “.NET Core” in the Compiler dropdown. interface screenshot

You can also import packages such as JSON.NET, EntityFramework, Linq and many others, see the full list here.

There ars quite a few features there:

There’s also a couple of other online C# execution environments, like or, but they don’t seem to support latest features of C# and look outdated, so .NET Fiddle stands out quite clearly from the crowd.

OAuth, JWT & OpenID

Authorisation tokens are not going anywhere any time soon, whether you like it or not. There is a tool that can help troubleshoot issues with auth tokens, such as invalid issuer/audience, elapsed expiry date, invalid credentials etc.

It can be really helpful to see the data stored in that encoded auth token, so that you can spot any obvious errors.

If you having authorisation issues between your browser and the backend, or between microservices, you can take the particular auth token in question, plug it into and see what exactly is stored in there. interface screenshot

JSON stuff

Generate C# classes from JSON documents as simple as copy, paste and click. It’s indispensable when you’re defining boundaries of your API / microservice or integrating new services into existing code base – just take an example JSON payload and turn it into C# class. interface

It lets you generate C# classes from other data, such as:

It also supports a whole heap of other languages, such as Go, Swift, Java, Ruby and many others.

JSON Formatter & Validators

There’s quite a few online JSON formatters and validators that you can use to transforms mangled JSON data into human-readable text.(Because let’s admit there’s so much software in this world that doesn’t care about the readability of JSON, like application log files, JSON stored in databases etc.

It’s also handy to be able to take any suspicious JSON that might be crashing your app or leading to otherwise unexpected behaviour during serialisation/deserialisation and get it validated just to be sure.

Here’s a couple of formatters that I found to be useful:

Mock data

Often you need to get a sizeable amount of data for your tests, like GUIDs, names & addresses, phone numbers and alike. The following tools can help with that:

guidgenerator offers the following functionality:

Fake Name Generator can generate non-existing identities, including data such as:

You can generate single profiles or request a whole bunch of them to be generated. The download link to a CSV file will be sent to your email after a reasonably short wait. generated CSV file


Bogus is a .NET package that lets you create fake data during runtime in C#, F# and VB.NET. It supports tons of different attribute types, such as:

It also supports a whole bunch of non-English locales, such as French, Arabic, Japanese, Russian, Indian, Chinese, Ukrainian etc.

Bogus has got very extensive API, totally check it out if you need to generate testing data in your code.

Generate .gitignore files for your projects easily with Just enter your language / IDE / Framework into the search box and Richard’s your father’s brother. You can add several keywords to generate a file that covers all of the tech you’re using. search results


There you go, here’s a bunch of tools to help you with Web and App development on .NET platform.

Is there a tool that you found to be super useful that’s not listed above? Hit me up on [email protected] or leave a comment below, and I will add it to the list!

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