What is a CSS Selector?

CSS selectors are one of the fundamental units of programming in web development and browser automation. They’re used to target specific elements in a webpage, either for styling, scripting, or data access. You can think of them as the primary interface between HTML, CSS, and Javascript.

#contact-form {}
button[type="submit"] {}
.list > .item:nth-child(2) {}

Within the context of browser automation and testing, CSS selectors are used to target elements for behaviors such as clicking, typing, and scrolling. Then, they’re also used for selecting what data you’d like to extract from a page, whether as text, HTML, screenshots, or videos. Automation libraries like Playwright extend this behavior with helpers for targeting text content, interactivity “role”, and more.

Let’s explore a practical example: Perhaps your script needs to create a new user account on a live webpage. You would use CSS selectors to find the correct form inputs. Then after you enter an email address and password, you would use another selector to find the button, triggering a click to submit the form.

How can BrowserCat help with CSS selectors?

BrowserCat’s fleet of headless browsers fully supports Playwright, giving you fast, consistent access to the complete range of CSS selectors within your browser automations and test suite.

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