Insomnia REST - The most intuitive cross-platform REST API Client ð´
rubular - A ruby based regular expression editor
Postman - The Collaboration Platform for API Development
RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.
Hurl.it - Hurl makes HTTP requests.
RegEx Generator - RegEx Generator is a simple-to-use application that comes with the brilliance of intuitive regex and is also helping you out to test the regex.