If you add alt via js, how will the search robot react?

Question

JavaScript

The site has more than 3000 pictures without alt. It was decided not to rewrite everything manually, but to add alt equal to the title closest to the h2 image. Does this make sense for a search robot or does it read pure html without scripts. And what do you recommend to do?

Answer 1

Daniil Sugonyaev test on the title for example.
- take the title
- add the text
- find the service on request from the series "how the search bot sees the site"
- look at the result
If the added text is there, then the alt should work

Answer 2

And what prevents Plato from asking a question?
Here