Loadmill

UseWebhook.com

Capture and inspect webhooks from your browser. Forward to localhost, or replay from history. Free to use

Vaadin

Build scalable UIs in Java or TypeScript, and use the integrated tooling, components, and design system to iterate faster, design better, and simplify the development process. Unlimited Projects with five years of free maintenance

kogiQA

A web UI automation tool that functions without the need for selectors. Every developer gets 500 actions per month for free

percy.io

Add visual testing to any web app, static site, style guide, or component library. Unlimited team members, Demo app, and unlimited projects, 5,000 snapshots/month