I am currently using Vue.js on a website project of mine.
The server that returns this Vue.js SPA will not be capable of computation or checks, and will only serve the static resources required to run the SPA in the browser, where all computation will then take place.
For SEO purposes, I want to ensure error pages are handled correctly. Currently, every URL returns a 200 OK
and serves the SPA which can confuse search engines for pages that are actually supposed to be invalid. What would be the correct way of telling both users and search engines that the page is invalid if I cannot change the response the server provides?
For context, the SPA will get data from an API on another domain.
I have looked at other questions that are similar, but they normally recommend server-side checks, a dedicated 404-page redirect or a soft-404 page. Server-side checks and a dedicated 404 page will not be possible, and I have read that soft-404 pages are disliked by search engines.
Is there any proper way to go about this?
I have seen this post, but it is quite old and only suggests a no-index tag, which still makes the page valid in the eyes of search engines, just not indexable.