Act vs ngrok

act is an open-source command-line tool that runs GitHub Actions workflows locally using Docker containers. It reads workflow files from .github/workflows/ and executes them with environment variables and filesystem configurations matching GitHub's hosted runners. The tool enables fast local feedback on workflow changes without requiring commits and pushes to a remote repository.

ngrok is Tunneling tool that exposes local servers to the internet for testing webhooks, APIs, and demos.. It is available under a freemium model. This tool falls under the developer utilities category.