Creator of LambdaXL here. Sharing a side project that I have been working on for the past couple of months now. LambdaXL is a no code platform that lets you upload an Excel spreadsheet and it will turn it into a web calculator that you can embed into your website or you can share a link to it directly.
It uses Excel under the hood to ensure full compatibility (formulas, cross sheet references, even charts) , unlike some of the other solutions online that converts your spreadsheet into PHP/JavaScript/Python/etc.
It also saves every request so you can see what your users are doing.
Here is an example of a calculator that gets generated: https://lambdaxl.com/query/embed/b3b05024-eac5-4443-a67d-52a...
The primary difference between the two products is that they translate your spreadsheet into a JavaScript function that can run clientside whereas we are actually using Excel to do the execution in our backend.
In terms of the pros and cons, I’d expect theirs to be faster, especially for simple calculations, since they don’t have the overhead of Excel connections that we do and can avoid the network connection if you run it clientside, whereas ours is more Excel compatible and comprehensive. For example, LambdaXL can support pivot tables and charts, but they can’t. Looking at their website, they say they support “100+ Excel formulas”. I believe Excel has around 460 formulas, and so some of the edge case / niche formulas are likely not supported.