betwixt

Betwixt is a desktop application that lets you watch and analyze web traffic on your computer using the same visual interface found in Chrome's developer tools. Developers typically use Chrome DevTools to inspect network requests inside the browser, but Betwixt brings that same panel to traffic outside the browser, covering any app or process on your machine.

To use it, you install Betwixt and then tell your operating system to route traffic through it. On macOS, Windows, and Ubuntu, this involves pointing the system's proxy settings to a local address that Betwixt listens on. If you only want to watch traffic from a single terminal window rather than all system traffic, you can set a one-line environment variable instead. Capturing HTTPS traffic requires an extra step to install a certificate, which is covered in a separate doc file.

The tool is built with Electron, which means it runs as a standalone desktop app across different operating systems rather than in the browser. You can download a prebuilt release or build it yourself from the source code. The README is brief and does not describe what analysis features the interface provides beyond what can be inferred from the Chrome DevTools network panel comparison.

The project is open to contributions and is licensed under the MIT license.