If you have to check the output of Prometheus metrics in your browser regularly, the plaintext format is not the most eye-friendly, especially for many values:

Prometheus metrics as plain text

So I wrote a simple browser extension to make scanning through the metrics easier with a little syntax highlighting and spacing:

Prometheus metrics with syntax highlighting

Since it is unfortunately not so easy to determine whether a plain text response is actually a collection of Prometheus metrics, the extension works by default on the usual paths ‘/metrics’, ‘/federate’, ‘/probe’, ‘/prometheus’ and ‘/actuator/prometheus’. If you click on the extension symbol, you can also define your own paths (regular expressions are supported).


You can download the browser extension directly from the Google Chrome and Firefox web stores. It also works in Microsoft Edge, but requires the Chrome Extension Web Store to be enabled as external source.

The source code for this is of course available at GitHub.