When should I use a CSS selector tester?

A CSS selector tester is essential whenever you need to validate selectors before implementing them in production scrapers.

Common use cases:

• Building new scrapers to ensure your selectors target the correct elements without unwanted matches
• Working with complex HTML structures where visual inspection is difficult (deeply nested tables, dynamic content)
• Debugging broken scrapers after a website update - quickly identify which selectors failed and why
• Collaborating with team members to document and validate selector strategies before code review
• Learning CSS selector syntax - experiment with different patterns and immediately see results without writing scraping code

Advantages over browser DevTools:

Unlike browser DevTools which require a live website, selector testers work with saved HTML files. This makes them perfect for:

• Testing against historical versions of pages
• Working with HTML samples provided by clients
• Comparing selector behavior across different page versions

When to use:

Use a CSS selector tester whenever you need confidence that your selectors will extract exactly the data you need, nothing more and nothing less. It's much faster to iterate on selectors in a dedicated testing environment than to deploy code and debug in production.