Is parallel creation of a page with a new layout but old text on the same domain not plagiarism?

Question

Search Engine Optimization

Greetings. I am rewriting the site code for SEO, under html5 with new main article etc tags.
And for online analysis of semantics, in particular on this site, I want to put a new html-page in the site directory. The text will be the same as on the main page, but with a new html code.
That is, I will have a working main page and a test one with exactly the same text, the same meta tags, and even the same title.
Question: Will search engines decide at the time of indexing non-unique content or plagiarism?

Answer 1

If it is a test page and you are afraid that the search engine might think badly of you, then as an option, this page can be thrown into disallow in robots.txt.

Answer 2

You can't use a robots.txt file to hide...
google doesn't care about disallow. He understands meta