Is it possible to promote a service consisting of one page in search engines?

Question

Search Engine Optimization

Created three single-page services of the same type for the sake of experiment.
https://charsmap.tk/ - Online character table
https://counttext.tk/ - Find text length online
https://difftext.tk/ - Find differences between texts online
Is it possible to somehow promote them in search engines and if yes, how?

Answer 1

If the topic is narrow and the site is useful to the user (determined through the behavioral factor), he will get into the top himself, even if it is a one-page site consisting of one screen.
If this is another clone for the purpose of monetization through advertising, then it is very unlikely.

Answer 2

Of course real. Google Kana to Romaji or Glitch Text Generator as examples.
And to advance as well as the rest now. Meta optimization and constant re-passing. And patience. And a bit of crowd marketing, if you want (be careful with links, otherwise hello filter). If I were you, I would add some other low-competitive keyword on the topic to the description instead of the main one. So that a couple of people a month improve your behavior. Expect results in six months or so.