if I would be you, I would check my use case and where and how the data be saved. If it's for example a database and you have a table like "start questions" and each questions can have many answers, I would do that (route approach). But if it's like a database and you have one user object and there a keys for something like "role", I would do it via a clientside multi step form

I have external backend in php and client in nextjs when we fill each step all that data for that step needs to be saved because if user leaves the page and come back the data needs to be there not to be filled over again

... that step needs to be saved ...

Then you can do it with the route approach, but keep in mind to have a clean redirect flow then. If you don't know how, you can still use a clientform

I need to create a shared layout for these 4 routes to look like spa

All that questions in multistep form will be for a user so all that data would be applied to that user that is filling it but first he needs to register and then start to fill multistep

yea, then you can still follow one of these approaches: https://nextjs-forum.com/post/1243855136376361042#message-1243882342221611132

@Scarlet Tanager solved?

I didn’t try yet

i did a proof of concept for a muli step multi route form recently. If you need the code i could separate it out in a repo. Let me know

Yes you can thanks