Requestly is an open-source tool that simplifies API development, testing, mocking, and integration for developers and QAs.

Percy is a visual testing and monitoring tool that focuses on detecting visual changes in web applications

Selenium automates browsers. That's it! What you do with that power is entirely up to you.

Comprehensive and user-friendly cloud platform for Load Testing, Speed Testing and Website & API Optimization and Monitoring

LangSmith Observability gives you complete visibility into agent behavior with tracing, real-time monitoring, alerting, and high-level insights into usage.

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol.