I've been using this tool since the open testing phase when they provided a balance of 25,000 credits, and the testing was completely free for everyone. Now, of course, I use it on a paid basis. The functionality is very extensive: you can scan pages, track all content changes, see how it affects search engines, and monitor positions, traffic, and indexing. SEO specialists will definitely appreciate the ability to work with keywords, their grouping, cleaning, and semantic extraction. It's important not to overdo it with the number of keywords, as this can quickly deplete your balance. I spend about 1,500 rubles a month on all my projects, while significantly saving on keywords. My colleagues with similar websites in terms of page count spend 2-3 times more, practically not limiting themselves in keyword usage.
