https://blog.scrapinghub.com/2016/10/27/an-introduction-to-xpath-with-examples
- videlibri: Template / XPath 3.0 / XQuery 3.0 / CSS 3 Selector / JSONiq Online Tester
- XPath Evaluator: Online XPath tester that supports XPath 3.0 and XQuery 3.0 via Saxon-HE 9.7 and XPath 1.0 via .NET XPath engine (GitHub).
- BeautifyConverter XPath Tester (requires free registration, sports many other useful online tools like minifiers, beautifiers, converters, validators, etc.)