What jsoup does
jsoup takes HTML from a string, file, or URL and builds a clean DOM (the element tree of the page). You then query it with jQuery-style selectors:
doc.select("div.price") returns every matching element, and you read each one's text or attributes. It also cleans up broken markup and can sanitize untrusted HTML - stripping out tags that could be unsafe. For pulling data from static pages, it is short to write and fast to run.When to use jsoup
Use jsoup when you are working in Java (or another JVM language) and scraping pages whose content is already in the HTML the server sends - product listings, articles, tables. It is a great fit for small-to-medium jobs where the data is right there in the initial HTML. It is not the right tool for JavaScript-heavy single-page apps, because jsoup does not run JavaScript - it only reads the HTML as delivered.
jsoup's limits for modern scraping
jsoup only parses HTML. It does not run JavaScript, rotate proxies (swap the IP address each request comes from), or handle anti-bot defenses. On a protected site you will receive a 403 or a Cloudflare challenge page instead of the real content, and on a single-page app you will get an empty shell with no data. The usual fix is to first fetch fully rendered HTML through a web scraping API, then hand that HTML to jsoup to parse.