When comparing ASP.NET Core vs B4X, the Slant community recommends B4X for most people. In the question“What are the best tools for making a cross-platform application?” B4X is ranked 1st while ASP.NET Core is ranked 10th.
Ranked in these QuestionsQuestion Ranking
Pro Fast and getting faster
Thanks to breakthroughs in ROSLYN compiler and the efforts of the .NET COre developer team, code written in C# can reach speeds just a step behind C++.
Pro Multi Platform
Can run on Windows, Linux and Mac (also Visual Studio Code editor).
Ability to host on IIS, Nginx, Apache, Docker, or self-host in your own process.
Pro Built-in middleware
Pro Ease of Use
Pro JSON optimization
In .NET Core 2.1 and 3.0, new APIs are added that make it possible to write JSON APIs that require less memory, using Span<T> and UTF8 strings, and improve throughput of applications like Kestrel, ASP.NET Core web server. See also Utf8JsonReader.
It is a very secure platform.
Both VS and VSCode are powerful free IDEs that are well integrated with ASP.net Core. VS Community also allows for commercial use for projects with less than 5 developers.
Pro Tutorials and documentation quality
Both microsoft and 3rd party tutorials are mostly of high quality and encourage you to use the industry best-practices.
Pro A very active forum where you can find any issue you have, and quick answers to new ones
Pro A highly motivated program author who is very active in the forums
Erel Uziel is simply the most pro-active Soft-Creator/Forum Manager you will ever come across. If it has not yet been asked & answered, just ask and you will be answered withing minutes, and thanks to it being a trully international forum, this is achieved 24h/7d.
Pro Very easy to use and powerful for IoT
Support for Bluetooth/BLE, MQTT, TCP/UDP, Serial, NFC, Websockets, HTTP/2 across platforms makes it the ideal tool for IoT projects.
Pro Create easy, fast and with less code cross-platform views
B4XUI custom views are designed, by Erel and other forum members, exactly with this in mind; custom views that act and feel exactly the same no matter what platform you target.
Pro Live code swapping
A huge productivity boost when you can run your apps on the devices and make code changes real time without needing to recompile.
Pro Powerful general purpose programming tool
As mentioned in its website, "With B4X, anyone who wants to, can develop real-world solutions."
Pro No complexities compared with other tools
No need to learn JAVA, C+, PHP, or any other complementary languages in order to achieve exactly what you need.
Pro Many informative video tutorials
The tutorials help beginners as well as more experienced programmers grasping important concepts.